Could not load file or assembly error - c#

Can anyone help me figure out what the problem is. I am trying to start up a C# winformsa app in visual studio and i keep getting this error:
Could not load file or assembly, Foo.dll version1.93343 or one of its dependencies
The system can't find the file specified
vs 2005, C# 2.0
any help

Typically it's about one of your references' reference, possibly deep down in the dependency tree. What I usually do is, fire up Sysinternals Process Monitor (http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx), filter by process name, and run the app. It's typically fairly easy at this point to sift through the FILE NOT FOUNDs and locate the offending missing reference.

Fire up Fuslogvw.exe and inspect which assembly (or reference) can't be found.

This is the key part: "or one of its dependencies"
I've often found that the assembly dll file that can't be loaded looks fine. However one of its dependencies (another assembly dll) does not exist or has been moved.
When the CLR loads an assembly it will also check that all of that assemblies dependencies exist. In XCopy deployment this normally means you need all the dependency assemblies in the same directory as your application exe.
Try loading the winforms executable into Reflector and under "yourApp.exe" expand the References node to see what the other referenced types are.

You must have a reference to Foo.dll somewhere and it can't be located (duh). Do you see a reference in the solution window? You can right click that and select "properties" to look at the path.

Do you see an exclamation mark on a reference in visual studio's solution explorer ?
If so, then you need to remove it then add it again.

Worth checking your global web.config hasn't got a reference to that assembly

Related

The system can not find the dll

I converted my console app to Class Library project so that I can use dll again for multiple project. I am getting an error
Could not load file or assembly 'System.Net.Http.Primitives,
Version=1.5.0.0, Culture=neutral, PublicKeyToken=b03f5f711d50a3a' or
one of its dependencies. The system can not find the file
I've already tried the solution mentioned here: Could not load file or assembly System.Net.Http.Primitives. Located assembly's manifest definition does not match the assembly reference.
But no luck. Any suggestion
1- check if you are referencing an assembly which in turn referencing an old version of unity. for example let's say you have an assembly called ServiceLocator.dll which needs an old version of Unity assembly, now when you reference the ServiceLocator you should provide it with the old version of Unity, and that makes the problem.
2- may be the output folder where all projects build their assemblies, has an old version of unity.
you can use FuseLogVw application to find out who is loading the old assemblies, just define a path for the log, and run your solution, then check (in FuseLogvw) the first line where the Unity assembly is loaded, double click it and see the calling assembly, and here you go.
Your problem posted here previously: Could not load file or assembly or one of its dependencies
Please search before rising your question. Thanks
try right click -> Properties -> Build Action -> Embeded Resource should make it work
I will show you clearly the mean of Lucky Lefty. In Solution Explorer, right click on you .dll file and choose properties. The properties pane appears then on Buil Action option, you choose Embeded Resource. After that, you rebuil your solution.
You can view more information from here: http://www.codeproject.com/Articles/528178/Load-DLL-From-Embedded-Resource
Remember: Google search is your best friend.

The type is defined in an assembly that is not referenced, how to find the cause?

I know the error message is common and there are plenty of questions on SO about this error, but no solutions have helped me so far, so I decided to ask the question. Difference to most of similar questions is me using App_Code directory.
Error message:
CS0012: The type 'Project.Rights.OperationsProvider' is defined in an
assembly that is not referenced. You must add a reference to assembly
'Project.Rights, version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.
Source File:
c:\inetpub\wwwroot\Test\Website\App_Code\Company\Project\BusinessLogic\Manager.cs
Following suggestions here and here, I have deleted all instances of Project.Rights.dll inside C:\Windows\Microsoft.NET/*.*
According to this, I checked if .cs files in question have build action set to "Compile". They do.
I have also double checked that the .cs file containing the "Project.Rights.OperationsProvider" type is deployed to App_Code directory.
For some reason, application is not looking for the type in the App_Code directory. Since I've deleted all instances of Project.Rights.dll (that I know of), I don't know which assembly the error message is mentioning.
When you get this error it isn't always obvious what is going on, but as the error says - you are missing a reference. Take the following line of code as an example:
MyObjectType a = new MyObjectType("parameter");
It looks simple enough and you probably have referenced "MyObjectType" correctly. But lets say one of the overloads for the "MyObjectType" constructor takes a type that you don't have referenced. For example there is an overload defined as:
public MyObjectType(TypeFromOtherAssembly parameter) {
// ... normal constructor code ...
}
That is at least one case where you will get this error. So, look for this type of pattern where you have referenced the type but not all the types of the properties or method parameters that are possible for functions being called on that type.
Hopefully this at least gets you going in the right direction!
Check target framework in the projects.
In my case "You must add a reference to assembly" actually meant, that caller and reference projects didn't have the same target framework. The caller project had .Net 4.5 , but referenced library had target 4.6.1.
I am sure, that MS compiler can be smarter and log more meaningful error message. I've added a suggestion to https://github.com/dotnet/roslyn/issues/14756
In my case this was because doing a NuGet package update had only updated references to a dll dependency in some but not all projects in my solution - resulting in conflicting versions. Using a grep-style tool to search text within *.csproj files in my solution it was then easy to see the projects that still needed to be updated.
When you get this error, it means that code you are using makes a reference to a type that is in an assembly, but the assembly is not part of your project so it can't use it.
Deleting Project.Rights.dll is the opposite of what you want. You need to make sure your project can reference the assembly. So it must either be placed in the Global Assembly Cache or your web application's ~/Bin directory.
Edit-If you don't want to use the assembly, then deleting it is not the proper solution either. Instead, you must remove all references to it in your code. Since the assembly isn't directly needed by code you've written, but instead by something else you're referencing, you'll have to replace that referenced assembly with something that doesn't have Project.Rights.dll as a dependency.
In my case, I was referencing a library that was being built to the wrong Platform/Configuration (I had just created the referenced library).
Furthermore, I was unable to fix the problem in Visual Studio Configuration Manager -- unable to switch and create new Platforms and Configurations for this library. I fixed it by correcting the entries in the ProjectConfigurationPlatforms section of the .sln file for that project. All its permutations were set to Debug|Any CPU (I'm not sure how I did that). I overwrote the entries for the broken project with the ones for a working project and changed the GUID for each entry.
Entries for functioning project
{9E93345C-7A51-4E9A-ACB0-DAAB8F1A1267}.Release|x64.ActiveCfg = Release|x64
{9E93345C-7A51-4E9A-ACB0-DAAB8F1A1267}.Release|x64.Build.0 = Release|x64
Entries for corrupted project
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.ActiveCfg = Debug|Any CPU
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.Build.0 = Debug|Any CPU
Corrupted entries now fixed
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.ActiveCfg = Release|x64
{94562215-903C-47F3-BF64-8B90EF43FD27}.Release|x64.Build.0 = Release|x64
I hope this helps someone.
It just happened to me that different projects were referencing different copies of the same dll.
I made sure all referenced the same file on disk, and the error disappeared as I expected.
Unloading and reloading the class library in Visual Studio solved this for me.
For me, this was caused by the project both directly and indirectly (through another dependency) referencing two different builds of Bouncy Castle that had different assembly names. One of the Bouncy Castle builds was the NuGet package, the other one was a debug build of the source downloaded from GitHub. Both were nominally version 1.8.1, but the project settings of the GitHub code set the assembly name to BouncyCastle whereas the NuGet package had the assembly name BouncyCastle.Crypto. Changing the project settings, thus aligning the assembly names, fixed the problem.
It didn't work for me when I've tried to add the reference from the .NET Assemblies tab.
It worked, though, when I've added the reference with BROWSE to C:\Windows\Microsoft.NET\Framework\v4.0.30319
I had this issue on a newly created solution that used existing projects. For some reason, one project could not "see" one other project, even though it had the same reference as every other project, and the referenced project was also building. I suspect that it was failing to detect something having to do with multiple target frameworks, because it was building in one framework but not the other.
Cleaning and rebuilding didn't work, and restarting VS didn't work.
What ended up working was opening a "Developer Command Prompt for VS 2019" and then issuing a msbuild MySolution.sln command. This completed successfully, and afterwards VS started building successfully also.
one of main reason can be the property of DLL
you must before do any thing to check the specific version property if it true make it false
Reason:
maybe the source code joined with other (old)version when you build it , but this Library upgraded with new update the version now different in the Assembly Cash and your application forbidden to get new DLL ,and after disable specific version property your applacaten will be free to get the new version of DLL references
Maybe a library (DLL file) you are using requires another library. In my case, I referenced a library that contained a database entity model - but I forgot to reference the entity framework library.
This can also mean you use a library, which exposes (public) types that are defined in a library. Even when you do not use these specifically in your library (the one that doesn't build).
What this probably prevents is you writing code that uses a class (which in its signature has the types from a library not referenced) that you cannot use.
For me the reason why the error appeared was that the WebForm where the error was reported has been moved from another folder, but the name of its codefile class remained unchanged and didn't correspond to the actual path.
Initial state:
Original file path: /Folder1/Subfolder1/MyWebForm.aspx.cs
Original codefile class name: Folder1_Subfolder1_MyWebForm
After the file was moved:
File path: /Folder1/MyWebForm.aspx.cs
Codefile class name (unchanged, with the error shown): Folder1_Subfolder1_MyWebForm
The solution:
Rename your codefile class Folder1_Subfolder1_MyWebForm
to one corresponding with the new path: Folder1_MyWebForm
All at once - problem solved, no errors reporting..
The type 'Domain.tblUser' is defined in an assembly that is not
referenced. You must add a reference to assembly 'Domain,
Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.
**Solved:**
Add reference of my domain library layer to my web app libary layer
Note: Make sure your references are correct according to you DI container
In my case this was because I used
Implicit Operator
between BLL and DAL classes.when I want to use BLL Layer In Application Layer I got this error.
I changed
implicit operator
to
explicit operator
it be OK.
Thanks
In my case the version of the dll referenced was actually newer than the one that I had before.
I just needed to roll back to the previous release and that fixed it.
I have a similar problem, and I remove the RuntimeFrameworkVersion, and the problem was fixed.
Try to remove 1.1.1 or
My problem was that the Output Type for one of my projects was set to Console Application. To fix this, I right-clicked the project, chose Properties, clicked the Application tab, and change Output Type (from Console Application) to Class Library. After I re-compiled, this error went away.
Clean your solution and rebuild worked for me (in Visual Studio, these are options you get when you right click in your solution explorer), the error is gone in my project.

Visual Studio could not load file or assembly; maybe cached?

When I run unit testing to serialize to an xml file, I keep getting error message:
Could not load file or assembly
'Company.Fin.Bank.Common.XmlSerializers.dll, Version=1.0.0.0,
Culture=neutral, PublicKeyToken=null' or one of its dependencies. The
system cannot find the file specified.
I guess Company.Fin.Bank.Common.XmlSerializers.dll may be in cache somewhere but it is impossible to find this dll, even though i don't need that dll. I want to remove it. But where can i find it? is it possibly in a cache? if yes how can i clean the cache from VS? This problem is very new to me.
What a weird part is that i used another laptop (win 7) to run the unit testing, there is no error message i got - it worked. but when i used my own laptop (win 8) i keep getting error message. I have no idea why.
I hope to find solution from you. Your help means alot. Thanks!!!
That assembly is dynamically generated by the framework (XMLSerializer)
In .Net implementation, the XmlSerializer generates a temporary
assembly for serializing/deserializing your classes (for performance
reasons).
Also, this may be normal behavior - is it stopping your application from running?
even though i don't need that dll
Visual Studio will usually remove unneeded DLLs. Typically this is caused by dependencies (which are harder to keep track of).
I want to remove it.
Check in the References of the project in the Solution Explorer. If any of them have a yellow triangle that means they can't be found (the project may still compile and run if you aren't actually using that reference).
is it possibly in a cache?
As Daniel Kelley mentioned C:\Windows\assembly and C:\Windows\Microsoft.NET\assembly are where the global assembly cache is located. If it isn't there check the Hint Path of the reference (it will show up in Properties).
Good luck finding your reference, keep in mind that you need not only the actual DLL but all of its used references in most cases. Also a decompiler like DotPeek can be useful if you need a more discreet way of looking at references.

C# DLL run-time error - builds, runs, but throws unhandled exception upon trying to use DLL functions

I am trying to compile the example project shown here for C#. It had to be converted to VS2010, but that worked fine. It builds, runs, but then dies when it tries to access a DLL function.
I made a series of images to show my steps. As you can see, the device I designed is attached and correctly configured, but I really don't think that has anything to do with the issue. Inside the Form1.cs file, the following comment explains how to use the DLL:
/*
PLEASE NOTE
You must add a reference to the FTChipIDNet.dll in order to use this sample
To do this:
1. Click on Solution explorer tab.
2. Right click the References tree.
3. Choose Add Reference option.
4. Browse to the FTChipIDNet.dll (as a personal preference I place this in my bin directory)
5. Click OK
*/
I followed the instructions shown above and the undefined reference to the namespace FTChipID was fixed. I also manually checked the Object Browser to be sure the GetNumDevices function exists and it does.
Clicking the button produces this error:
DLLNotFoundException was unhandled:
Unable to load DLL 'FTChipID.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)
at this line of code:
FTChipID.ChipID.GetNumDevices(ref numDevices);
Now, you may be thinking "the error says it needs FTChipID.dll, not FTChipIDNet.dll." I'm wondering the same thing. I have FTChipID.dll along with a .lib and .h file, but I don't know how to use them or where they need to be in order for this program to find them. I tried adding a reference to FTChipID.dll, but VS2010 said
A reference to ...\FTChipID.dll could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component.
I don't know what that means either. Any ideas? Thanks in advance.
FTChipIDNet.dll is a wrapper for the FTChipID.dll, so you need to add the reference to your solution (as you did above) and then copy the FTChipID.dll to the bin folder there FTChipIDNet.dll will be located.
Both dll's should be located in your solution's bin folder to operate and should not be located in windows\system32.
I built the FTDI sample program "CSChipID" in VS2013 using a build to "Any CPU". The two DLL files "FTChipID.dll" and "FTChipIDNet.dll" were copied to the bin directory, but I continued to get errors when the first DLL function was called, "FTChipID.ChipID.GetNumDevices(ref numDevices);" The fix is change the build to "x86" as follows.
Build - Configuration Manager
Active Solution Platform - "x86"
Note: If "x86" is not available, select -New...- to select "x86".
It sounds like there are multiple .dll's: both FTChipIDNet.dll (the one you interface to), and FTChipID.dll (the one with the actual, non-COM, non-.Net functionality). You need both.
SUGGESTION: Copy both to your \windows\system32 directory

C#: cannot find assembly file

I am getting an error back from a DLL saying it cannot create an instance of one of classes in my solution because it cannot find the assembly file.
If I am debugging a solution, do I need to put a copy of certain assembly files in other locations?
EDIT:
In my compiled solution all the DLLs (including the proprietary ones) all go in the app directory and it works fine. But I am trying to work out where the files should do in order to debug the solution.
Put the assembly in question in 1) the same directory, or 2) in the GAC, or 3) use AssemblyBinding to define the specific path that the .NET framework.
MSDN link: using AssemblyBinding to define the referenced assembly path
I think you have forgotten to add reference of the assembly to the project.
Add the reference, and try again.
Read more here -> http://msdn.microsoft.com/en-us/library/7314433t%28VS.80%29.aspx
If they are in your references list, try right-clicking the problem reference in the solution explorer and selecting "properties". There is one property called copy local. Make sure that is true. Then when you build, a copy of that dll will be in your bin folder.
You can add an event handler to AssemblyResolve to find out which library it tries to load. Some sample code and ideas can be get from this question.
Update
To find out, what is the best place for your project you should take a look into How the Runtime Locates Assemblies guide. Also to get a live view about where the framework searches for your needed dll you can use ProcessMonitor to see where it tries to catch it.

Categories

Resources