Could not load file or assembly 'System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'

Question

I have this error on my VisualStudio 2017 Wep API Project:

Could not load file or assembly 'System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

StackTrace:

=== Pre-bind state information ===
LOG: DisplayName = System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
 (Fully-specified)
LOG: Appbase = .../WebApp/
LOG: Initial PrivatePath = ...\bin
Calling assembly : System.Runtime.CompilerServices.Unsafe, Version=4.0.3.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a.
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: ...\web.config
LOG: Using host configuration file: ...\IISExpress\config\aspnet.config
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Redirect found in application configuration file: 4.0.0.0 redirected to 4.1.1.0.
LOG: Post-policy reference: System.Runtime, Version=4.1.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/Temporary ASP.NET Files/vs/30ca8c3f/b4b96212/System.Runtime.DLL.
LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/Temporary ASP.NET Files/vs/30ca8c3f/b4b96212/System.Runtime/System.Runtime.DLL.
LOG: Attempting download of new URL file:///D:/DSTS/WF/WF1_0/WebApp/bin/System.Runtime.DLL.
WRN: Comparing the assembly name resulted in the mismatch: Build Number
ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.

Can't precise exactly when it stars to happen but was either after the update to Visual Studio (to version 15.3.2) or the update of the wep Api packages.

Some other problems emerge, that i solved already, but now i am stuck in this error. The calling assembly is System.Runtime.CompilerServices.Unsafe. My first guess was to downgrade this package and the packages dependent on this, witch i already did but without success.

I also try the reinstall of all packages in the solution, check for failed assembly references (there were a few), check for duplicates package versions. No luck.

Update: After a few more bumps, the System.Runtime is now present on the reference folder but marked yellow (missing). I just reinstall the 'System.Runtime' package, so or either my solution is corrupted or the package as a bug. Target framework is 4.7

Answer 1

Just for the closure of this question that is unanswered for a long time, the solution to set the binding in the config, so when a different version of the dll is required, the .net framework knows that is allowed to serve with a different version.

This fix should work if there is a compatible version of the dll package with the application.

The explanation on how to set bindings for any dll is answered here:

https://stackoverflow.com/a/29497528/2700303

Answer 2

In my case, when opening a solution with Visual Studio 2017 and getting this error, to resolve this issue I had to combine the following:

1) In "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\devenv.exe.config"

find any occurrence of "..\..\MSBuild" and replace it with "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild"

2) I noticed that my Microsoft.Build.Framework.dll was missing from the folder, did a search and found it under "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\amd64\". Copied it to "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE"

3) Again, in deven.exe.config, changed

codeBase version="15.1.0.0" href="C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\Microsoft.Build.Framework.dll"

to the version found in the amd folder, in my case: codeBase version="15.3.409.57025" href="C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\Microsoft.Build.Framework.dll"

I am assuming this is related to the fact that I installed VS2017 Enterprise v15.3 and either something was/got corrupted or it is a bug.

In no case is this a permanent fix but for now it works fine for me and has unblocked my progress. Will update if I find something new.