FatalExecutionEngineError with Microsoft.EntityFrameworkCore 2.0.2 referenced in .NET 4.6.1

[RussKeldorph]

From @dalibor983 on March 22, 2018 9:42

When I run IISExpress everything working great until I rebuild project and IISExpress tries to reload new dlls in memory. Then I get this exception when DbContext is initialized that crashes IISExpress:

Managed Debugging Assistant 'FatalExecutionEngineError' 
  Message=Managed Debugging Assistant 'FatalExecutionEngineError' : 'The runtime has encountered a fatal error. The address of the error was at 0x73b03293, on thread 0x6b90. The error code is 0xc0000005. This error may be a bug in the CLR or in the unsafe or non-verifiable portions of user code. Common sources of this bug include user marshaling errors for COM-interop or PInvoke, which may corrupt the stack.'

After starting IISExpress again everything working again.

I must restart IISExpress on every new build :(

Copied from original issue: dotnet/coreclr#17121

[zd-dalibor]

I think that maybe Roslyn compiler causes the problems with projects that combines .NET framework and netstandard. I notice that when I kill "VBCSCompiler.exe" process my IISExpress does not crash after project rebuild.

I em not sure because I don't know what this "VBCSCompiler.exe" process does in background. Does it build project silently in the background (independently of visual studio) or what?

[divega]

This issue was moved to dotnet/roslyn#25687

[jaredpar]

I think that maybe Roslyn compiler causes the problems with projects that combines .NET framework and netstandard. I notice that when I kill "VBCSCompiler.exe" process my IISExpress does not crash after project rebuild.

Why do you believe this is a roslyn compiler problem? Is there bad IL generated that is causing this?

Killing the server means it falls back to the command line compiler here which will produce the exact same output.