Short Version
I found myself losing alot of time renaming + including files in my Xamarin.Forms Projects because any change from Upercase to Lowercase (or vice versa) only in the files, will result in no change what so ever in the Project file, so i have a few questions:
Is there an option in Visual Studio that makes it take into account file renaming from Upercase to Lowercase? (See Edit Below)
What's the best way of changing alot of files from Upercase to Lowercase without delete/re-adding them?
Is renaming the file includes in the .csproj directly a Good Practice? if not, what is the best for this kind of scenarios?
Longer Version + Adicional Info
I had to include over 2000 images (Android + iOS and their respective sizes). So i started copying the files into the correct directory and include them in the Mobile Projects, the problem came when i already included the files in the project and some of the files had Uppercase letters that i haven't noticed before, so i made changes by hand to all the files, when i noticed that those changes weren't reflected in the Solution Explorer/Project File, i tried manually and got this error:
Edit: It seems this issue was apparently resolved in VS2019 arround v.16.1, but only if the file wasn't renamed externally. Since i did that i got this warning. This anwsers my first question.
And one solution that i found was renaming like: Foo.png > fooo.png > foo.png
But that would be exponentialy time-consuming by the number of files i had to edit, so i made this piece of code:
string filepath = #"C:\Users\(...)";
DirectoryInfo d = new DirectoryInfo(filepath);
foreach (var file in d.GetFiles("*.png", SearchOption.AllDirectories))
{
if (file.Name.Any(char.IsUpper))
{
File.Move(file.FullName, file.FullName.Replace(file.Name, file.Name.ToLower()));
}
}
What it does is basically create a new file but with Lowercase, that means i still have to Remove the old References and Include the new Files. This doesn't seem right since a simple rename would do.
What's my go to option here?
Windows as operating system is ascendant of the operating system where there was no difference in lower and uppercase. As such at today's state Windows treats the files with same letters as the same though technically it can remember and display lower and upper cases in file names.
Overall it means your request is not natural in Windows. Maybe someone can provide you with some hack, but if you want to resolve this problem quickly move your project to the Mac where this works differently at the operating system level, perform your operation in Visual Studio for Mac and then you can continue to use Windows if you prefer.
EDIT: Actually I can tell you one hack for Windows. First rename file to whatever you want (like add 1 at the end) and then rename it to the desired file name. It will work properly.
I had the same issue. In my case the files were in the .csproj (Project File) with lowercase name. Removing the affected lines from .csproj fixed the problem.
In Visual Studio 2019 -
Right click on the project name in Solution Explorer -> select "Edit Project File"
Find the offending file under ItemGroup, you can either remove the line or edit the filename. I have not had any side effects by removing the file as I know what I am doing, your mileage might differ.
Just incase cut and paste the delete or rename before hand in Notepad in case you want to go back, Ctrl-z works too :)
I'm not sure if anyone else has encountered this but often, when I open this particular solution, I see a whole list of errors (see below).
If I double click one of them, then Visual Studio seems to wake up and the errors relating to that particular cs file disappear. This isn't a critical issue and is more on an irritation than anything else but I wonder, is there perhaps something wrong with my code that's causing this false-positive or is it random Visual Studio behaviour?
I had this problem too.
Deleting bin and obj folders not work.
Cleaning solution not work.
Various platform I need to be as is.
Helped me close solution and delete folder .vs, which is often full of problematic mess. After opening solution all false errors disappeared.
As mentioned in a comment, you can do a Clean and Rebuild. If that does not work for you, you can browse to the solution folder and within each of the project folders delete the bin and obj folders. Then perform a build.
You may also want to look into your Configuration Manager and ensure that all of your projects are set to the same Configuration (Debug/Release) and Platform (Any CPU/x86/etc...) and marked to build for that configuration.
Finally, you may also want to check the Build Order for your solution. Ensure that projects are all built in the proper order.
-- Edit:
On thing brought up in comments that I will add here was to make sure that any library projects in the solution are added as Project References rather than referencing the output DLL directly.
Something that has only become evident in later years, and is only relevant upon reflection on this old question, is that the particular solution that we experience this issue in contains a Website project and NOT a WebApplication project. This became evident when we started to look deeper into these recurring errors and noted that they only ever related to codebehind files and all had to do with the Control Name not existing in the current context.
Amongst the various differences between the two project types, it seems that the lack of designer files for each ASP page may be a contributing factor. The error disappears as soon as you double click it potentially indicating that VS is not able to keep track of the control references until you open the relevant page / codebehind file.
We're moving over to a Web Application as a temporary measure.
Hope this insight helps someone else!
After a struggle with creating a database (first with an entity framework, after without), we have a database (and an EntityModel_HFFContext file we don't use, it's not connected). Normal work proceeded, and I installed a NuGet-package for an MVC sitemap.
From that moment, the project worked fine, but after a couple of days two warnings came up about two files missing: "The parent file, 'EntityModel_HFF.tt', for file 'locatie.cs' cannot be found in the project file." ("HFF" is the project name in here) and then those multiplied themselves into errors: "Source file 'locatie.cs' cannot be found" in a CSC file I cannot find.
These two files ('locatie.cs' and 'klant.cs') are not in any view, but somehow they are displayed outside all folders, saying they do not excist (see this screencapture). I have tried to delete those files manually, but that did not have any success. I have tried some other ways too, but that resulted into the complete deletion of the database, so now I am somewhat desperate.
I have no idea where to look and what to do, to get rid of these two files (or probably references to these files, since we don't use them at all), so I don't have these errors anymore. Has anyone of you have a clue of where I need to look (e.g. where this CSC file is) and what I need to adjust to fix this?
Maybe it can be useful to know I use Visual Studio 2013.
Update
I fixed the errors by unloading the project, editing the .csproj file and commenting out
<Compile Include="klant.cs">
<DependentUpon>EntityModel_HFF.tt</DependentUpon>
</Compile>
(and the other one too). Now these errors are gone - is this a safe way to do this?
The reason why you get the error is because when you deleted the locatie.cs and klant.cs file, you didn't remove them from the project solution itself, therefore, Visual Studio is expecting the file to be part of the project but is unable to find them, which explains the yellow warning signs.
Like what you said, all you have to do is to remove the files from the solution as they no longer exists. So yes, it is safe to comment out that portion in the .csproj file.
Although, I would like to mention that you didn't have to go to that much trouble, all you had to do was to delete the file in your solution in Visual Studio, since they no longer exists anyway.
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've got a Visual Studio C# project which is under version control (SVN).
I've always commited and updated the project without any problems. But a couple of hours ago Visual Studio throws the following error when I try to launch/rebuild the project:
Files has invalid value "<<<<<<<
.mine". Illegal characters in path.
I don't know how to fix this problem. What should I do?
That happens when svn encounters a conflict: You changed a file, the file on the server was changed and it cannot (easily) be merged automatically. You need to decide what is the correct solution now.
Subversion just adds the diff into your source file (and creates files next to it, called OriginalName.mine (unchanged) and OriginalName.rsomething (unchanged, server version)).
Fix the conflict and tell subversion that this is resolved.
just delete the obj folder and it will worked fine.
Remove the code that shouldn't be in the file throwing the error and remove the the three files with extensions .mine, .<somerevision> and .<some_other_revision>. svn updated files that now contain 'conflicts' and you need to resolve these conflicts by hand. Usually this means you edited a file, someone else edited the same file and checked in changes and you didn't pay attention when checking out the changed file.
Delete every thing you have in obj folder .
Remove your obj folder from svn version control . Because on every build it get updated and when other developer commit changes to solution SVN is unable to marge obj folder files and raise error
Files has invalid value "<<<<<<< .mine". Illegal characters in path.
Please read the Basic Usage chapter in the subversion book. It has a section about Merging conflicts by hand which explains the conflict markers you're seeing.
Removing the debug folders worked for me (see comment-not answer above).
I got this after moving 12 folders from one section of svn to a new section. So if you get this after moving a project and the error does not point to an actual file, this is likely your issue.
If you have AnkhSVN or VisualSVN installed resolving this is most likely as easy as right clicking the file in the solution explorer and selecting edit conflict.
This will open the changed file in your merge editor. (See Tools->Options->Source Control->Subversion User tools for AnkhSVN). With a good merge tool like the free to use SourceGear DiffMerge or TortoiseMerge, resolving the conflict is just a few mouseclicks away.
I have had this happen on a large scale where the files get marked resolved but the conflict metadata is still there. I wrote a regular expression for visual studio to find these, for instances where it is not feasible to simply revert the changed files.
http://www.codetunnel.com/blog/post/90/ever-merge-with-svn-and-mess-up-when-resolving-conflicts-read-on
I closed the IDE, then deleted the obj folder and restarted the IDE and rebuilt my Code. This worked for me.
Inside your project :
odj folder -> Debug -> project name.csproj.Filelistabsolute.txt(snb.csproj.Filelistabsolute.txt)
Inside the text file
>>>>>>>.mine and >>>>>>>.r150 occurs
to remove the things the program works
1)Just save your local changes whatever u have edited in the file
2)revert the file
3)update it from SVN
4)Paste your local changes
If you are using TortoiseSVN you should have a right click option on the file called Edit Conflicts. This should bring up TortoiseMerge which is able to read those obnoxious notations stuck into the file (really, to break your code so you KNOW there's an issue and don't blindly check it in).
TortoiseMerge will read it properly and present you with a 3-way merge. This was what I was looking for. Although it is true that it does also create the separate .mine and .rxxx and .ryyy files, and there are various manual and command-line ways to deal with all this.
Have a simple solution. just delete all file from debug folder and rebuild the solution, an error display on the screen "There were build errors. Would you like to continue and run the last successful build? click on "Yes" button. Now stop the program and run normally.