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I have stumbled into an issue that is really annoying.
When I debug my software, everything runs OK, but if I hit a breakpoint and edit the code, when I try to continue running I get an error:
Metadata file 'XYZ' could not be found
After looking around for a while, I found some a similar issues, but they were all regarding a build failure, which is not my case (this happens only after edit-continue).
What I have tried so far:
My code is compiling and running.
I cleaned the solution and restarted VS.
I made sure that the missing file's project is being build for the configuration I am running (in configuration manager).
I manually built the missing file's project.
Some extra info:
It does not matter what I change, still get the same error (the change is not related to the missing file).
This happens also when I pause and continue (not only breakpoints)
I am running the project using a custom configuration (configuration manager...). When I run it using the default Debug configuration the error does not occur.
Any ideas?
Eventually what solved the issue was:
Clean every project individually (Right click> Clean).
Rebuild every project individually (Right click> Rebuild).
Rebuild the startup project.
I guess for some reason, just cleaning the solution had a different effect than specifically cleaning every project individually.
Edit:
As per #maplemale comment, It seems that sometimes removing and re-adding each reference is also required.
Update 2019:
This question got a lot of traffic in the past, but it seems that since VS 2017 was released, it got much less attention.
So another suggestion would be - Update to a newer version of VS (>= 2017) and among other new features this issue will also be solved
As far as I can tell, this happens when the project dependencies gets messed up for whatever reason (whilst all the inter-project references are still intact). For many cases, it is NOT a code issue. And for those who have more than a few projects, going through them one at a time is NOT acceptable.
It's easy to reset project dependencies -
Select all projects and right click unload
Select all projects and right click reload
Rebuild solution
For those who have an issue in their code or some other issue that's causing this problem you'll obviously have to solve that issue first.
One possible reason could be you have upgraded the some of your projects (in the solution) to higher version e.g. from .NET 4.0 to 4.5 This happened in my case when I opened the solution in VS 2013 (originally created using VS 2010 and .NET 4.0). When I opened in VS 2013 my C++ project got updated to .NET 4.5 and I started to see the problem.
Generally this kind of error comes with human mistakes like if we change the namespace in some improper way, or changing folder names from explorer for current project etc, where compiler is unable to detect sometimes.
I came across the same error, to resolve which I tried few steps. Please follow all the steps :
Clean whole Solution
Right Click on every Project in your solution , Go to Properties and make your Default namespace as well as Default assembly name same as in your code (i.e namespace before class name)
Check Folder names for each project by going through the explorer(Where your project solution is). If not matching with your project names, make it similar (Like step 2) to them.
Remove all your references from each project relevant to another of same solution, and add it again.
In Your Project Solution folder, you will find Visual c# Project file. Right click and open with Notepad. In your initial lines you would find for lines for every project like below:
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "**Client**", "**Client** \ **Client**.csproj", "{4503E259-0E3B-414A-9074-F251684322A5}"
EndProject
Check again Foldernames (I have highlighted in BOLD) and make it similar to what you did in step 2.
Clean the whole solution again
Build The Solution (If doesn't work try building individual after cleaning again)
Make sure all your dependent projects are using the same .Net Framework version. I had the same issue caused by a dependent project using 4.5.1, while all others were using 4.5. Changing the project from 4.5.1 to 4.5 and rebuilding my solution fixed this issue for me.
XYZ couldn't be found because is not built yet....
Right click on the solution and check Project Dependencies, the Project Build Order should also change according to the dependencies that have been set.
The only thing that worked for me was to delete the Solution User Options (.suo) file. Note that, this is a hidden file.
To locate this file, close your Virsual studio and search for .suo from the file explorer within your project.
PS: a new .suo file will be created again when you rebuild your project and hopefully this newly created one wont give you issues.
I hope that helps someone get rid of this anoying error :).
I had this problem for days! I tried all the stuff above, but the problem kept coming back. When this message is shown it can have the meaning of "one or more projects in your solution did not compile cleanly" thus the metadata for the file was never written. But in my case, I didn't see any of the other compiler errors!!! I kept working at trying to compile each solution manually, and only after getting VS2012 to actually reveal some compiler errors I hadn't seen previously, this problem vanished.
I fooled around with build orders, no build orders, referencing debug dlls (which were manually compiled)... NOTHING seemed to work, until I found these errors which did not show up when compiling the entire solution!!!!
Sometimes, it seems, when compiling, that the compiler will exit on some errors... I've seen this in the past where after fixing issues, subsequent compiles show NEW errors. I don't know why it happens and it's somewhat rare for me to have these issues. However, when you do have them like this, it's a real pain in trying to find out what's going on. Good Luck!
Well, my answer is not just the summary of all the solutions, but it offers more than that.
Section (1):
In general solutions:
I had 4 errors of this kind (‘metadata file could not be found’) along with 1 error saying 'Source File Could Not Be Opened (‘Unspecified error ‘)'.
I tried to get rid of ‘metadata file could not be found’ error. For that, I read many posts, blogs etc and found these solutions may be effective (summarizing them over here):
Restart VS and try building again.
Go to 'Solution Explorer'. Right click on Solution. Go to Properties. Go to 'Configuration Manager'. Check if the checkboxes under 'Build' are checked or not. If any or all of them are unchecked, then check them and try building again.
If the above solution(s) do not work, then follow sequence mentioned in step 2 above, and even if all the checkboxes are checked, uncheck them, check again and try to build again.
Build Order and Project Dependencies:
Go to 'Solution Explorer'. Right click on Solution. Go to 'Project Dependencies...'. You will see 2 tabs: 'Dependencies' and 'Build Order'. This build order is the one in which solution builds. Check the project dependencies and the build order to verify if some project (say 'project1') which is dependent on other (say 'project2') is trying to build before that one (project2). This might be the cause for the error.
Check the path of the missing .dll:
Check the path of the missing .dll. If the path contains space or any other invalid path character, remove it and try building again.
If this is the cause, then adjust the build order.
Are you using a database code generation tool like SQLMETAL in your project?
If so, you may be facing a pluralized to unpluralized transition issue.
In my case, I have noted that some old pluralized (*) table names (upon which SQLMETAL adds, by default, an "s" letter at the end) table references to classes generated by SQLMETAL.
Since, I have recently disabled Pluralization of names, after regerating some database related classes, some of them lost their "s" prefix. Therefore, all references to affected table classes became invalid. For this reason, I have several compilation errors like the following:
'xxxx' does not contain a definition for 'TableNames' and no extension method 'TableNames' accepting a first argument of type 'yyyy' could be found (are you missing a using directive or an assembly reference?)
As you know, I takes only on error to prevent an assembly from compiling. And that is the missing assemply is linkable to dependent assemblies, causing the original "Metadata file 'XYZ' could not be found"
After fixing affected class tables references manually to their current names (unpluralized), I was finnaly able to get my project back to life!
(*) If option Visual Studio > Tools menu > Options > Database Tools > O/R Designer > Pluralization of names is enabled, some SQLMETALl code generator will add an "s" letter at the end of some generated table classes, although table has no "s" suffix on target database. For further information, please refer to http://msdn.microsoft.com/en-us/library/bb386987(v=vs.110).aspx
Hope it helps!
I had this error come up. I followed all of the solutions here but nothing worked. I was using Visual Studio 2013 Professional. I couldn't get the individual project rebuilds to work and I finally figured out there was a circular dependency in my references. Visual Studio does a pretty good job normally of warning you if you are adding a reference to something that references back, but for some reason it didn't in this instance. I added a reference to a project that referenced the project I was working on - and it accepted it. VS bug perhaps?
My 5 cents.
This problem started after a solution wide clean.
I managed to get the problem to go away by setting the Active Solution configuration in: Build -> Configuration manager to release. Then build and set it back to debug again. The build succeeded after that.
Close VS, locate and remove the 'packages' folder from outside of visual studio. Restart VS and build -> all dependencies are reinstalled
Visual Studio 2019 Community 16.3.10
I had similar issue with Release build. Debug build was compiling without any issues.
Turns out that the problem was caused by OneDrive. Most likely one could experience similar issues with any backed-up drive or cloud service.
I cleaned everything as per Avi Turner's great answer.
In addition, I manually deleted the \obj\Release -folder from my OneDrive folder and also logged to OneDrive with a browser and deleted the folder there also to prevent OneDrive from loading the cloud version back when compiling.
After that rebuilt and everything worked as should.
this happens because of the difference of names in the folder name and namespace name. If u create a namespace in a certain name , and later you rename it the namespace will have the old name itself. And the compilation will take the old path to find the .dll and .exe file . To avoid this open the .csproj file of each namespace with a text file , and find the old path in the file.
remove this, clean and rebuild the solution. This worked for me. I spent an entire day working on this problem.
I had this and managed to fix it using this SO answer:
Metadata file '.dll' could not be found
I had to uncheck all of the boxes, click Apply, reenable all of the checkboxes and then click apply again, but it fixed the problem.
I just ran into this issue and after an hour of screwing around realized I had added an aspx file to my product that had the same name as one of my Linq-To-Sql classes.
Class and Page where "Queue".
Changed the page to QueueMgr.aspx and everything built just fine.
For a new build, it could be that some dependencies aren't installed. For me it was Crystal Reports.
It happens when one project dll is failing and that is referenced by number of projects. So first fix it and then Build individuals.
I ve had this problem and it has started after importing our solution to TFS as a new project.I came across this topic and found a quick solution with some inspiration from your answers.
All i needed to do is to rebuild the project thats supposedly lost its metadata file and voila , problem solved.
There's also one another silly reason which you should check with patience... as it occurred to me after wasting 4hours searching for answers:
The story to me was that I accidentally changed a small line of code among thousands of c# class files and then trying to rebuild the solution. As you could imagine, I ended up with 40+ meta data file missing errors and with 1 compilation error among them -- which I didn't check carefully, purely thinking all errors were the same!
after 4 hours searching and then accidentally double checking my error list, I found that silly code error, fixed it, compiled, and then error disappeared.
Not a good answer to your problem, but do hope my case wasn't same to yours.
I had the same problem. In my case I had by mistake I had set all the projects apart from the project with the main method as console application.
To resolve I went to every project other than the one with main function and right click> properites > output type > class library
it was happened to me because I've a strange clash in the namespaces:
I had
AssemblyA
with namespace
AssemblyA.ParentNamespace
witch defines ClassA
and in the same assembly another namespace with name
AssemblyA.ParentNamespace.ChildNamespace
witch defines a different ClassA (but with the same name)
I had then in AssemblyA.ParentNamespace IInterfaceB witch had a method that in the beginning returns IEnumerable and a ClassB witch implements IInterfaceB
I had later modified the method in ClassB to return IEnumerable but I've forgot to update the IInterfaceB definition, so the method there was still returning IEnumerable
the fun fact was that the solution still complile if I did a rebuild all, but the tests witch refers AssemblyA didsn't work and returns the "Metadata file could not be found"error.
updating InterfaceB to correctly return IEnumerable as its implementor ClassB did solved the problem, unfortunately the error message was vague and also the fact that the compilation worked makes me suppose that maybe there is something to fix in the compiler
A coworker was running into this problem and the cause was eluding us. Eventually we realized that the project directory (and therefore the path to the NuGet packages) contained %20 (thanks, some Git gui tool which shall not be named) and the error messages showed that the compiler was looking for an very similar-looking path but one which had to %20, rather a space. Apparently something in the build system somewhere performs HTML-decoding on local filesystem paths.
Renamed the working copy directory and everything started working.
I had this issue too.
It started after I did a little folder tidying in my project.
I then tried to compile and got many duplicate class errors. (despite them not being duplicated. I think the linking was just out of wack)
Upon checking these, the errors would all disappear leaving only the "Metadata file ...debug\application.exe could not be found" error.
I solved this by looking in the build output window to find which classes were duplicated.
I would then right click the class name and "go to definition".
there will be two definitions to select from, open them both, the second definition will seem to open the same file again, however the second one will identify as the error source(red underline).
Delete all the code out of the file and save(This will not effect your actual file).
This should now compile correctly.
Ensure that there are no spaces in the path to your project...
I am using Windows 10 with Visual Studio Community 2019 and I was cloning a multi project solution as it was from a GIT repo. I was having this error with all other dependencies in the solution along with a E_POINTER error. Its path, inherited from GIT, had spaces like C:/repos/MY PROJECT NAME/ ...
I deleted it, cloned it again and make sure that its path contained no spaces like C:/repos/MY_PROJECT_NAME/ ...
That fixed my problem.
I had same issue too.
In my case, I recently add an internal class to somewhere in project. One of the dependencies in solution has same class name and both of them are added correctly to references.
I changed my last activity and rebuild, it works.
Be sure that your compiler messages are valid. In my case I catch reference error from there, not listed as an error in Error List.
I got project, named Perfect. VS 2012 Ultimate, all updated.
I got a window with xmlns:Properties="clr-namespace:Perfect.Properties" in the header
I keep getting error:
The name "Settings" does not exist in the namespace "clr-namespace:Perfect.Properties".
Project compiles, builds and runs fine though. What the hell is with my visual studio?
I got another solution, from which I simply copied the code, there is no such error there.
UPD: There are other namespace troubles, like it can't find my custom Combobox item in my own namespace delcared like xmlns:local="clr-namespace:Perfect.Misc" and used <local:VoidComboItem exchange="All available" />. Class exists and works in runtime, but design editor is not working at all, so I have to use XAML and run app to see changes.
I assume you are talking about a WPF app...
1- In most cases this happens when you have other compiler errors, is this the only error you have?
2- also try changing the target to Release and rebuild, then switch back.
3- keep VS updated
Most likely your solution is on a network share (see https://stackoverflow.com/a/16218145/647151).
Try mapping the network share to a drive and then open your solution from there.
When I try to build my solution, I get the following error:
Visual Studio cannot start debugging because the debug target 'c:\target' is missing. Please >build the project and retry, or set the OutputPath and AssemblyName properties appropriately >to point at the correct location for the target assembly.
My output path is set correctly to bin\Debug, but the exe is never created in that folder. Instead, all I get are the exe.config, vshost.exe, and vshost.exe.config files.
Any idea what's going on?
Make sure that output path of project is correct (Project > Properties > Build > Output path)
Go in menu to Build > Configuration Manager, and check if your main/entry project has checked Build. If not, check it.
Go to properties > Application , and select the output type of your project
I've had the same problem;
Here are solutions that didn't work for me:
Building/rebuilding entire solution
Making sure the output path was correct (MyProject > Properties > Build > Output > Output path)
Here's the solution that did work for me:
Rebuilding just the project
You could open the project file with a text editor and replace 'c:\target' by 'bin\Debug'
EDIT
There are other more helpful answers but I can't delete mine since it's the accepted one.
#CZFox Answer
#Yehuda Shapira Answer
steps for changing target path is
Go to Properties
Then go to Debug
Browse the Start external program and select the bin/Debug/.exe file
I have solve this type of problem follow this step
1.VS2010 right click on the solution explorer and select the Build.
Again press Ctrl+F5 or F5
You can try the following steps to resolve the problem.
Step 1:
Right click on the solution and select the property
Step 2:
In Configureation property select the Build option button
I just stumbled across this problem, but I'm using Visual Web Developer Express 2010 and couldn't find any wrong path either within IDE or in the project file. Rebuilding or deleting build folders didn't help.
But after examining the projects .user file, which I've never done before, I discovered that the bad path was in there. Very simple if one knows where to look.
I had the same problem and the real solution was embarrassingly easy:
If, in your project, Visual Studio has never successfully compiled the program (before finding the first bug), you will get this error. What I did was remove all offending code (in my case, leaving just a simple button1_Click with no code). Run/Compile the code one time; exit the running program, and this message goes away.
The Compiler builds various directories and files on a first successful compile and these are used by the debugger. I am now recommending with all new projects, define the form, compile, close, and then begin coding.
I've found that this can happen if all the files are deleted from the bin folder. ReBuild the app to force a full build: right click on the project in solution explorer and select ReBuild.
Please follow the below steps to overcome this problem:
If you are working with VS2010, change platform target to x64
Select .net framework as 3.5
If you are using any custom code for Sharepoint and like to debug or deploy the use the above....and my bad sake i dont abt the .net applications
I had this error too (in VS2010), and in my case (two projects in one solution, with one being for unit tests) the answer was to go into the solution's (not the project's) properties and set a single startup project. I would've thought it also necessary, in that project's settings, under Application, to specify the "Startup Object", but it's working for me with or without that.
Although this has already been answered, I found that my own solution was none of the above. Admittedly a rookie mistake, within my solution I had multiple projects, and thus when trying to run solution, the wrong project was set as the Startup Project.
So in my own case, not to say others, the solution was to right click the project and select Set as Startup Project
I tried everything mentioned in this thread but none worked.
Then, i tried the simplest thing and it worked.
Close visual studio and open it back up again.
This was a really annoying error!
I kept trying to start a debug instance but it just wouldn't make an exe! Though there were errors in my ConnectionString (while trying to make an SQL connection). There were two backslashes that were supposed to be a part of a path and the tutorial I was following told me to ignore it.
Well, turns out that was the error. A backslash marks the beginning of some escaping that you want to do, and the way to have a backslash displayed is \\ instead of \.
Got rid of that, and it worked for me.
EDIT: It would seem that you have to get rid of the tiny errors that you have made while writing your code to let it compile properly.
I have solved this problem by changing the Platform Target to "any CPU".
If the above explanation does not help you, then you could have error in the program. I have the same issue and I solved it as I cut the functions used in the same class and one of the functions were the cause of it.
I had a very very similar problem, but almost non of the solutions worked for me, finally when i reset the VS setting, it fixed...
To reset settings:
Tools Menu >
Import and Export Settings >
Select Reset all settings radio >
Next >
Next (You can backup your current settings in this step) >
Finish
Problem:
The problem was I had bad nuget source configuration, so the solution could not start properly despite the fact it was build correctly because it still saw old dll references.
Solution:
It was not enough to change nugget source url, I just had to remove entire nugget source and add it again with proper url.
Clean solution and rebuild it.
There are many issues that can lead to this problem, after losing 2 days to this issue I think I have the root cause of this issue and also the problem of the Form Designer throwing an error when switching to the Design view (also seems to effect the DataSet Designer):
A language syntax error that Intellisense doesn't catch.
Once I went through my code with a fine tooth comb I found a couple of really boneheaded mistakes that I kept overlooking, once those were resolved the solution compiled just fine and the output was in the correct place.
Here is the solution for this problem, no need to change anything for this problem.
You all know C# is case sensitive language and we have to write all methods and statements in correct case.
We all are just missing this thing and we just have to change method 'main() --> Main()'
This thing solved my problem please let me know if you still find any :-)
Specifically the error occurs in the Resources.Designer.cs:
Error 2 The namespace 'ModulusFE' already contains a definition for 'StockChartX' Resources.Designer.cs 11 21 ModulusFE.StockChartX
I've googled this and am still quite confused. Does anyone know anything I might try?
I have tried rebuilding and cleaning, as well as renaming the Resources.Designer.cs file in hopes that it would rebuild, but no luck.
The top of the code says this:
// <auto-generated>
// This code was generated by a tool.
// Runtime Version:4.0.30319.225
//
// Changes to this file may cause incorrect behavior and will be lost if
// the code is regenerated.
// </auto-generated>
Any ideas whatsoever would be appreciated.
Looks like a bug in VS code's OmniSharp.
Solution for me was to execute command "Restart OmniSharp".
Just do:
- ctr shift P
- type "Restart OmniSharp" .. hit enter
This fixed it for me.
I had this happen to me about a year ago and I don't remember exactly what the root cause was, but there are two things you might try:
If it's an auto-generated file (as 'Resources.Designer.cs' tend to be), try deleting it and letting VS re-generate it.
Either separately or in conjunction with #1, select Show All Files in the Solution Explorer or open the solution folder in Windows Explorer - it could be that a version of the file somehow got excluded from the project and is therefor 'invisible' to VS but still makes it angry...
I've had this problem, too, and it was because I created a new namespace, but the parent namespace contained a class with the same name.
This is an old question but I didn't find the fix I used, so I've added it here.
In my case it was a namespace with the same name as a class in the parent namespace.
To find this, I used the object browser and searched for the name of the item that was already defined.
If it won't let you do this while you still have the error then temporarily change the name of the item it is complaining about and then find the offending item.
Unfortunately, none of the other answers helped.
My problem specifically occurred in a WPF project.
The problem arose when I created a folder under the MainWindow folder, which effectively created a namespace something like ProjectName.MainWindow.Folder.
Now, I believe because of some static designer code, Visual studio gets confused between the class MainWindow and the namespace Project.MainWindow.Folder .
As a solution, I moved the Folder out of MainWindow. Looking at the Class View or the solution/project helps to recognize what namespaces and classes within them exist.
This just happened to me. What happened was that I duplicated a project that was originally under source control. Although I properly renamed everything, the file permissions on all the files were still set to read-only. When I started modifying some form controls, Visual Studio automatically created a Resource1 file because the original Resource file was read-only.
What I did to fix this was as follows:
allow write permissions on the project files.
deleted the original Resource file
Ctrl-A for all form elements, then Ctrl-X to cut them.
Save the form.
Ctrl-V to paste them all back.
Save the form.
I had to do this because the auto-generated code wasn't updating on it's own, so I "forced" it to update by making a change to the form. Not doing this left a bunch of code from form elements that no longer existed prior to changing the file permissions.
I had an xaml file with the following definition
<Window x:Class="mm2.Views"
.etc..
/>
mm2.Views was the name of a namespace in my app.
To fix it, I correctly renamed the xaml object:
<Window x:Class="mm2.Views.RecordedTracks"
.etc..
/>
I had a similar problem and resolved it by removing any copies/backups of the .cs file from the directory.
I had this same problem and it was due to naming a function in the code behind the same as my tool. Simple mistake but something to keep in mind as well.
I had a similar issue however found a different solution than what I have read. I came to my fix after reading P Walker's answer.
My issue happened when I named my resource file for Japanese language incorrectly. Long story short I was trying to create a Resource for Japanese but I accidentally named it localized.jp.resx. I then realized that the iso language code is ja not jp for Japanese. Once I changed the file name to localized.ja.resx and deleted everything that was in the designer file it fixed my problem.
This is what fixed my problem hopefully it helps someone else.
I came across a similar problem. After generating my database from an edmx file, I clicked 'save all' and 'build' and all the Types/Model classes that I created showed up in the error box. I researched why this happened and like your replies suggest, I thought it was something that was auto-generated.
However, solutions like deleting the auto-generated classes and re-generating them didn't work for me.
I eventually ran out of patience and decided I'd fix it another way. Since my script was saved, I just deleted the edmx file (and its reference in the web.config) and went back and created another one using "model from database" and didn't touch it after that.
Needless to say, I was pretty mad that it turned out like that.
Me too got this error,
When I change my WPF project's Target Framework to Framework Version 4.0 Client Profile -> Framework 4.0. It's solved by itself.
The way I solved it was to remove all of the enums from the model browser, and then re-add them again. Somehow miraculously the tool regenerated everything perfectly and the error message went away (I'm using VS2012, FYI).
What helped me many times, was just turning it off and on again..
Ctrp + shift + P -> Reload window in VS Code
Close and open the project/window.
Cleaning all bin, obj contents (in power shell)
Get-ChildItem .\ -include bin,obj -Recurse | foreach ($_) { remove-item $_.fullname -Force -Recurse }
After this, it can be that I am missing something else, like some package reference or include, but usually it is, that underlying parser/compiler (omnisharp) just gets messed up and needs some restart to work properly again.
This may be a bit of an edge case, but we've run across this in our development environment from time to time. We had to setup a custom culture in Windows to support en-HK. Windows 8.1 now supports this culture natively as does Windows 2012 R2, but older machines need to have the culture created. Any machine that does not have this culture setup will get this error reported. The solution is to create the culture on the machine (We have a console app created for this purpose) and everything starts working again.
I had the same issue just now, and I found it to be one of the simplest of oversights. I was building classes, copying and pasting code from one class file to the others. When I changed the name of the class in, say Class2, for example, there was a dropdown next to the class name asking if I wanted to change all references to Class2, which, when I selected 'yes', it in turn changed Class1's name to Class2.
Like I said, this is a very simple oversight that had me scratching my head for a short while, but double check your other files, especially the source file you copied from to ensure that VS didn't change the name on you, behind the scenes.
If you are using different aspx.cs files that define classes of the same name you can use
<compilation targetFramework="4.5" />
under <system.web> in your web.config file.
Although I would still strongly advise that you would change the class name.
This is not the best solve, but if you really don't care it is an easy solution.
I simply renamed my class. So I had class Card and I changed it to MyCard.
I think this issue is because you have added for a single table, 2 DAL classes.
If this table is included in a relation, then remove the table_name.dbml for it, and keep that for the related tables.
You must use one of them.
I had a similar problem (Universal project, Visual Studio 2015), I solved it with the following changes:
In App.xml.cs was (it was ok):
namespace Test.Main {
Wrong, old version of App.xml:
x:Class="Test.Main"
Good, new version of App.xml:
x:Class="Test.Main.App"
I had something similar to this happen in my WPF application. It arose when I was trying to do some cleanup by declaring a namespace that was more descriptive. The problem arose because I had named the namespace in the code-behind (or cs) the same as the Window class. The namespace in the code-behind should have the last section stripped (after the rightmost dot) and used to declare the class and instantiate it. Notice Win below:
xaml
<Window x:Class="FrameApp.UI.Invoice.Win" ...>
code-behind
namespace FrameApp.UI.Invoice
{
public partial class Win : Window
{
public Win()
}
}
An obvious oversight but it set me back at least an hour with all the errors that appeared.
I had this issue, but mine was slightly different to the issues mentioned here. I was cleaning up my project and moving around some classes into new folders. I had a 'AddFilter' class that I moved into an 'AddFilter' folder - so I had actually wound up with a class that was sharing the name of a namespace. This was a bit tricky to spot at first because I couldn't find any other classes that it was conflicting with; it was conflicting with the namespace instead.
If you copy&paste your pages don't forget to rename class names. Otherwise you get this error also with "Type already defines a member called 'OnGet' with the same parameter types"
look this happend to me when I created new file inside a folder with the same name of class in the project { folder name : Folder } and there is class name { Folder } so the namespace was the namespace.Folder so that the compiler assume that the cass defined in two places
in new file :
namespace APP.Folder
{
partial class NewFile
{
// ....
}
}
in the other file (the file that hase the problem):
namespace APP
{
partial class Folder
{
// ....
}
}
-- so you can edit the folder name or remove the .Folder from the namespace at the new file
I know this is an older post, but I thought it might help someone else if I shared my experience with this error. For me, I was working in Visual Studio 2019 and using Xamarin Forms. I received this error message when I created a new folder and named it the same as a Content Page I had made previously. Apparently we're not supposed to do that...
Anyways, I had to rename the folder then go through to each individual Content Page within the folder are change their namespace (in their .cs file) as well as the x:Class within their ContentPage tag (in their .xaml file) to reflect the folder's new name.
That's what worked for me. I hope it is helpful to someone else in the future should the error rise again.
I've had this problem recently, all i did is rename the file and class then build. then return again the original filename. It worked.
This happened to me, I noticed that there was actually another class with that same name under the same namespace "OtpService.Models.Request", so all I did was to just change the namespace of the 2nd class to "OtpService.Models.Request.ExtraObj". I did this because I did not want to change the name of the conflicting class to anything else.
I came across this partial class problem in a winform of a solution after converting from .net 4.5.1 to 4.7.2.
Initially the problem the compiler was not complaining about partial class but the use of properties.default...without qualification. After adding Global::solnNameSpace. qualifiers, then I got the partial class problem.
after viewing answers in this thread, I look at the resource designer file, I found it was generated with explicit solnNameSpace while the classes in the solution did not. Also the solnNameSpace is the same as the name of the problematic class name.
To fix the problem with the least effort and time I backed out Global... qualifier and removed the explicit namespace ... and end statements from the resource designer file. I know I may get in trouble later on if there were changes that cause auto generation of the resource designer file but I was was under tight deadline. I made documentation on the temp change instead of a better long term solution since the solution is under no change allowed for nature of the solution and multi project use.
I had this problem. It was due to me renaming a folder in the App_Code directory and releasing to my iis site folder. The original named folder was still present in my target directory - hence duplicate - (I don't do a full delete of target before copying) Anyway removing the old folder fixed this.
when you have tried everything else and still get the same trouble, there is a way out; however it will be tedious and need careful preparation.
Start another new project using existing files, or edit the project .csproj file if you are proficient in editing csproj (need backup). I will list steps for new project.
preparation:
note all references and their sources
note all included files from another project
rename the orginal projectname.csproj file
close solution/project
start new project using existing files(you will get errors from references)
add back the noted references
include/add existing file from other project(s)
When I try to build my solution, I get the following error:
Visual Studio cannot start debugging because the debug target 'c:\target' is missing. Please >build the project and retry, or set the OutputPath and AssemblyName properties appropriately >to point at the correct location for the target assembly.
My output path is set correctly to bin\Debug, but the exe is never created in that folder. Instead, all I get are the exe.config, vshost.exe, and vshost.exe.config files.
Any idea what's going on?
Make sure that output path of project is correct (Project > Properties > Build > Output path)
Go in menu to Build > Configuration Manager, and check if your main/entry project has checked Build. If not, check it.
Go to properties > Application , and select the output type of your project
I've had the same problem;
Here are solutions that didn't work for me:
Building/rebuilding entire solution
Making sure the output path was correct (MyProject > Properties > Build > Output > Output path)
Here's the solution that did work for me:
Rebuilding just the project
You could open the project file with a text editor and replace 'c:\target' by 'bin\Debug'
EDIT
There are other more helpful answers but I can't delete mine since it's the accepted one.
#CZFox Answer
#Yehuda Shapira Answer
steps for changing target path is
Go to Properties
Then go to Debug
Browse the Start external program and select the bin/Debug/.exe file
I have solve this type of problem follow this step
1.VS2010 right click on the solution explorer and select the Build.
Again press Ctrl+F5 or F5
You can try the following steps to resolve the problem.
Step 1:
Right click on the solution and select the property
Step 2:
In Configureation property select the Build option button
I just stumbled across this problem, but I'm using Visual Web Developer Express 2010 and couldn't find any wrong path either within IDE or in the project file. Rebuilding or deleting build folders didn't help.
But after examining the projects .user file, which I've never done before, I discovered that the bad path was in there. Very simple if one knows where to look.
I had the same problem and the real solution was embarrassingly easy:
If, in your project, Visual Studio has never successfully compiled the program (before finding the first bug), you will get this error. What I did was remove all offending code (in my case, leaving just a simple button1_Click with no code). Run/Compile the code one time; exit the running program, and this message goes away.
The Compiler builds various directories and files on a first successful compile and these are used by the debugger. I am now recommending with all new projects, define the form, compile, close, and then begin coding.
I've found that this can happen if all the files are deleted from the bin folder. ReBuild the app to force a full build: right click on the project in solution explorer and select ReBuild.
Please follow the below steps to overcome this problem:
If you are working with VS2010, change platform target to x64
Select .net framework as 3.5
If you are using any custom code for Sharepoint and like to debug or deploy the use the above....and my bad sake i dont abt the .net applications
I had this error too (in VS2010), and in my case (two projects in one solution, with one being for unit tests) the answer was to go into the solution's (not the project's) properties and set a single startup project. I would've thought it also necessary, in that project's settings, under Application, to specify the "Startup Object", but it's working for me with or without that.
Although this has already been answered, I found that my own solution was none of the above. Admittedly a rookie mistake, within my solution I had multiple projects, and thus when trying to run solution, the wrong project was set as the Startup Project.
So in my own case, not to say others, the solution was to right click the project and select Set as Startup Project
I tried everything mentioned in this thread but none worked.
Then, i tried the simplest thing and it worked.
Close visual studio and open it back up again.
This was a really annoying error!
I kept trying to start a debug instance but it just wouldn't make an exe! Though there were errors in my ConnectionString (while trying to make an SQL connection). There were two backslashes that were supposed to be a part of a path and the tutorial I was following told me to ignore it.
Well, turns out that was the error. A backslash marks the beginning of some escaping that you want to do, and the way to have a backslash displayed is \\ instead of \.
Got rid of that, and it worked for me.
EDIT: It would seem that you have to get rid of the tiny errors that you have made while writing your code to let it compile properly.
I have solved this problem by changing the Platform Target to "any CPU".
If the above explanation does not help you, then you could have error in the program. I have the same issue and I solved it as I cut the functions used in the same class and one of the functions were the cause of it.
I had a very very similar problem, but almost non of the solutions worked for me, finally when i reset the VS setting, it fixed...
To reset settings:
Tools Menu >
Import and Export Settings >
Select Reset all settings radio >
Next >
Next (You can backup your current settings in this step) >
Finish
Problem:
The problem was I had bad nuget source configuration, so the solution could not start properly despite the fact it was build correctly because it still saw old dll references.
Solution:
It was not enough to change nugget source url, I just had to remove entire nugget source and add it again with proper url.
Clean solution and rebuild it.
There are many issues that can lead to this problem, after losing 2 days to this issue I think I have the root cause of this issue and also the problem of the Form Designer throwing an error when switching to the Design view (also seems to effect the DataSet Designer):
A language syntax error that Intellisense doesn't catch.
Once I went through my code with a fine tooth comb I found a couple of really boneheaded mistakes that I kept overlooking, once those were resolved the solution compiled just fine and the output was in the correct place.
Here is the solution for this problem, no need to change anything for this problem.
You all know C# is case sensitive language and we have to write all methods and statements in correct case.
We all are just missing this thing and we just have to change method 'main() --> Main()'
This thing solved my problem please let me know if you still find any :-)