Could not load file or assembly Microsoft.CodeAnalysis

Question

Could not load file or assembly Microsoft.CodeAnalysis

I have a webproject I am trying to host, but when the server tries to compile it, I get the following error:

Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.CodeAnalysis, Version=1.1.0.0, 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) ---> System.IO.FileLoadException: Could not load file or assembly 'Microsoft.CodeAnalysis, Version=1.0.0.0, 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)
--- End of inner exception stack trace --- at Microsoft.CodeAnalysis.CSharp.CommandLine.Program.Main(String[] args)

So the server has an older version of CodeAnalysis than my project. So lets try a binding redirect!

<dependentAssembly>
    <assemblyIdentity name="Microsoft.CodeAnalysis" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-9.9.9.9" newVersion="1.0.0.0" />
</dependentAssembly>

Sadly, I still get the same error. What am I doing wrong?

c#

visual-studio

asked on Stack Overflow Mar 4, 2016 by

yesman • edited Dec 2, 2016 by

yesman

6 Answers

I figured this out myself. To anyone reading this, the problem was that the Nuget package Microsoft.CodeDom.Providers.DotNetCompilerPlatform (which also contains the CodeAnalysis package) was the wrong version. I created a new webproject, updated the offending Nuget package right away, and the problem was solved.

answered on Stack Overflow Apr 5, 2016 by

yesman

I resolved this issue but ensuring that the version numbers of the assemblies in my web.config were correct.

Edit:

I hit this problem as well and some may wonder how the Web.Config can become incorrect. In my case I am using Web.Config Transforms so the Web.Config file gets overwritten:

Changing the version number in Web.Configs compiler (in the Web.Template.Config) to the number matches the NuGet version does solve the issue:

<compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.5.0

answered on Stack Overflow Jan 16, 2017 by

Mark • edited Jun 9, 2017 by

Jeremy Thompson

Other possible fix (at least for Visual Studio 2015):

Get the latest Visual Studio update.

You can check for updates by going to Tools/Extensions and Updates/Updates

Same as this Q/A: Visual Studio 2015: Quick Actions no longer working, error: Could not load file or assembly Microsoft.CodeAnalysis

answered on Stack Overflow Mar 28, 2017 by

Don Cheadle • edited May 23, 2017 by

Community

I have had this problem today while doing an Umbraco v7.13.0 upgrade, simply updating the following package has fixed my problem, this is apparently a common problem with things like Umbraco upgrades.

Update-Package -Reinstall Microsoft.CodeAnalysis.CSharp

answered on Stack Overflow Jan 11, 2019 by

Nurhak Kaya

If none of mentioned options work, please go for this answer. Basically, you are registering that Microsoft.CodeAnalysis.dll to GAC

Could not load file or assembly 'Microsoft.CodeAnalysis, version= 1.3.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependenc

answered on Stack Overflow May 24, 2017 by

Dhrumil Bhankhar

Right click on your project >> Manage Nuget packages manager for solution >> Tap on Updates >> Update your 'Microsoft.CodeDom.Providers.DotNetCompilerPlatform' >> and then run your project again.

answered on Stack Overflow Dec 15, 2018 by

Sujeet Kumar Yadav • edited Dec 15, 2018 by

Klaus Gütter

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