17.10 is causing MissingMethodException exceptions on upgrade

[jaredpar]

A number of customers reported the following error when moving to 17.10.
 

Unhandled Exception: System.MissingMethodException: Method not found: ‘System.Collections.Generic.IEnumerator1<Microsoft.CodeAnalysis.NodeStateEntry1<System.ValueTuple2<System.__Canon,System.__Canon>>> Microsoft.CodeAnalysis.NodeStateTable1.GetEnumerator()’.	... C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Current\Bin\Roslyn\Microsoft.CSharp.Core.targets	85

This is caused by using the 7.0.4xx NET SDK in VS 17.10. Those SDKs are not technically supported in this release but the feedback on this bug is strong enough that we're going to try and move forward with a patch to this problem.

In the meantime customers who hit this can work around it in a few different ways. The preferred work around is moving to a newer .NET SDK which is supported like 8.0.2xx or 8.0.3xx. If that is not possible then customers can do the following for individual projects hitting this issue:

dotnet add package Microsoft.Net.Compilers.Toolset --version 4.9.2

For larger solutions it’s likely easier to set that in a Directory.Build.props file so that impacts all projects:

<Project>
  <ItemGroup>
    <PackageReference Include="Microsoft.Net.Compilers.Toolset" Version="4.9.2">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
  </ItemGroup>
</Project>

Note This is a temporary solution. Please uninstall this package after the fix is in 17.10 otherwise you will end up hitting issues with future Visual Studio updates.

[JuanZamudioGBM]

This is caused by using the 7.0.4xx or 8.0.1xx .NET SDK in VS 17.10. Those SDKs are not technically supported in this release but the feedback on this bug is strong enough that we're going to try and move forward with a patch to this problem.

Is this mentioned in the release notes or somewhere else? I was not aware that those SDK's were not supported, If I had known I wouldn't have updated my VS.

[danroth27]

Is this mentioned in the release notes or somewhere else? I was not aware that those SDK's were not supported, If I had known I wouldn't have updated my VS.

@JuanZamudioGBM Please refer to the .NET support policy here: https://dotnet.microsoft.com/platform/support/policy

[JuanZamudioGBM]

@danroth27 reading that page I would not have been able to figure out that 8.0.1xx was not supported in 17.10.
I know 7.xx is not supported any more but it would have been nice seeing a warning telling what SDK's were no longer supported in 17.10

Thanks for your time.

[danroth27]

@danroth27 reading that page I would not have been able to figure out that 8.0.1xx was not supported in 17.10. I know 7.xx is not supported any more but it would have been nice seeing a warning telling what SDK's were no longer supported in 17.10

@JuanZamudioGBM Ah, that's a good point. The .NET SDK versioning and lifecycle is covered here and the latest 8.0.1xx SDK is still supported (@jaredpar updated his above comment accordingly). So, if you're seeing problems with the latest 8.0.1xx patch, please let us know!

[paul-schroeder-msft]

So, I updated our global.json file to use version "8.0.300" of the SDK and that resolved the initial issue. However, we are now getting a ton of these errors during compilation (mostly in our test projects):

error CA1861: Prefer 'static readonly' fields over constant array arguments if the called method is called repeatedly and is not mutating the passed array

There are a handful of other errors, too. Yet, we have an .editorconfig file at a higher level with the following statement:

## Avoid constant arrays as arguments
dotnet_diagnostic.CA1861.severity = warning

It is like the build process is now ignoring our .editorconfig file and treating the diagnostic as an error instead of a warning. This might be a separate issue, which I'm still investigating, but it only started happening once we moved to a newer .NET SDK as recommended in this thread.

[jaredpar]

@paul-schroeder-msft believe that you're running into this issue with editorconfig priorities

dotnet/roslyn#72889

[paul-schroeder-msft]

So, to solve this in the near term, what I did in order to get things compiling via Visual Studio, my local command line, and our build pipeline is:

1. Change the SDK version in our global.json file to 8.0.300
   

2. Add this to the .csproj files for affected projects (because of the new compilation errors mentioned in a prior comment above):

	<PropertyGroup>
		<AnalysisLevelStyle>9.0</AnalysisLevelStyle>
		<NoWarn>CA1861,SA1101,SA1200,SA1629,SA1633</NoWarn>
	</PropertyGroup>

Thanks @jaredpar for the assistance!

[jaredpar]

Closing as 17.10.2 is now released

[SamehSaeed]

C# interactive window stop working on 17.10.2, it does not open at all, even after clean installation for windows & visual studio community

[jaredpar]

@SamehSaeed please open a new issue on dotnet/roslyn for that as it's seemingly unrelated to this particular problem.