Could not load file or assembly or one of its dependencies

Question

I'm having another of these "Could not load file or assembly or one of its dependencies" problems.

Additional information: Could not load file or assembly 'Microsoft.Practices.Unity, Version=1.2.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

I have no idea what is causing this or how I could debug it to find the cause.

I've done a search in my solution catalogs .csproj files, and every where I have Unity I have:

Reference Include="Microsoft.Practices.Unity, Version=2.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL"

Can't find any reference anywhere which goes against 1.2.0.0 in any of my projects.

Any ideas how I should go about solving this?

Solution 1

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 FusLogVw to find out who is loading the old assemblies, just define a path for the log, and run your solution, then check (in FusLogvw) the first line where the Unity assembly is loaded, double click it and see the calling assembly, and here you go.

Solution 2

Open IIS Manager

Select Application Pools

then select the pool you are using

go to advanced settings (at right side)

Change the flag of Enable 32-bit application false to true.

Solution 3

For me, none of the other solutions worked (including the clean/rebuild strategy). I found another workaround solution which is to close and re-open Visual Studio.

I guess this forces Visual Studio to re-load the solution and all the projects, rechecking the dependencies in the process.

Solution 4

Try to clean Debug and Release folders in your solution. Then remove and add unity again.

Solution 5

At 99% the Could not load file or assembly or one of its dependencies problem is caused by dependencies! I suggest you follow this steps:

1. Download Dependency Walker from http://www.dependencywalker.com/

2. Launch Dependency Walker and open the dll (in my case NativeInterfaces.dll)

3. You can see one or more dll with the error in red Error opening file...

4. It means that this dll is missing in your system; in my case the dll name is MSVCR71.DLL

5. You can download missings dll from google and copy in right path (in my case c:\windows\system32)

6. At this point, you must register the new dll in the GAC (Global Assembly Cache): open a DOS terminal and write:

    cd \Windows\System32
    regsvr32 /i msvcr71.dll
   

7. Restart your application

View more solutions

Comments

[decyclone]

Could any of your referenced assemblies be using some stuff in old Unity library?

[ronag]

Probably... but how can I find which assemblies? I have a lot of projects in my solution and a lot of potential suspects... trial and error bruteforce seems a bit hopeless...

[decyclone]

You only have to look into the referenced assemblies in the project for which you get this error.

[user1703401]

It's not the assembly reference, you reference version 2.0. But at runtime, the CLR is finding 1.2, an old version. If you don't see that old DLL in your build directory then use Fuslogvw.exe to find out how the CLR found this old copy.

[coggicc]

Look at your project's bin folder and see if your project's dll has a conflict in it's name. Just delete that one and then Rebuild your solution. That worked for me.

[Matt]

Possible duplicate of Could not load file or assembly 'Microsoft.Practices.Unity'

[Paul McCarthy]

"or one of its dependencies" is the part that really annoys me. If it can't load "one of its dependencies" the error should say which "one of its dependencies" can't be loaded. The current form is useless, it might as well say can't load thinggy

[Scott Rippey]

This issue can be caused by a lot of things ... your solution solved my problems, and might solve others' as well.

[Martin]

IIS -> select each ApplicationPool -> Basic Settings -> check if the latest framework is selected under the ".NET Framework version" dropdown

[botenvouwer]

@ScottRippey This worked for me to. I first deleted all .pdb files and then reloaded my project and rebuild it.

[Stiger]

Where's the log file of FuseLogVw

[eran otzap]

You can also right click your project in VS . and remove the prefer 32 bit checkmark

[RedGreenCode]

To avoid having to find the log file, you can specify a custom log path: Settings, check the Enable custom log path checkbox, enter a custom log path, refresh.

[Muflix]

I dont have "Solution -> Package" in my VS2010 project

[Dhir Pratap]

Dependency walker is great, but copying random DLLs from the internet to Windows is ... less great. It's better to try to find the installer that provides those dlls.

[meekash55]

Thanks. It worked. Well it was already True in my case , just for try. I made it False and it worked.

[Draex_]

Does not work with Community editions of Visual Studio

[Mykola Tarasyuk]

I believe there should be another issue, not related to Visual Studio edition. I tested the extension on VS 2017 and VS 2015 Community editions. Actually it was developed by means of VS 2017 Community edition.

[Draex_]

Aha. Do you have any other extensions installed? This page says that DGML is not supported in VS Community: msdn.microsoft.com/en-us/library/hh871439.aspx#VersionSuppor‌​t

[Mykola Tarasyuk]

There are no architecture tools in the Community edition but the DGML editor itself it available. You can install it selecting "Install DGML editor" under "Individual Components" -> "Code Tools" via Visual Studio Installer -> Modify

[samneric]

This worked for me although it was web.config, not app.config

[Bonez024]

Spent so long on this and I cannot believe this was the answer. It's usually good go-to solution when you're seeing some odd behavior within VS. Thank you.

[cheriejw]

I got a few files (API-MS-WIN-CORE-KERNEL32-PRIVATE-L1-1-1.DLL) not found and led me to this stackoverflow question. Basically keep in mind could be looking at false positive for some files, link provides more detail.

[Iannazzi]

This took me hours to figure out.... I accidentally named my unit test project the same name as the main project, so the unit test project dll must have been overwriting the project dll

[Keith Ketterer]

After checking application pool, "Enable 32-Bit Applications" was set to False, but my platform target was x86. Changing it to Any CPU OR x64 fixed my issue.

[Appsum Solutions]

When I merged a project from 1 server to another, this flag was indeed False again, thanks for the solution!

[Zujaj Misbah Khan]

Excellent! My dll file name and the namespace were different, I copied the namespace and renamed my dll.

[Mike Lowery]

stackoverflow.com/questions/516730/…

[stevejoy32]

Yeah, same here, combined with doing a Clean Solution. After I did that, VS highlighted a build error that wasn't showing up before. Previously it said Rebuild All Succeeded after rebuilding - I was referencing the wrong namespace for a class.

[Burhan]

Worked for me, I just deleted the bin/ folder and built the solution again.