Problem reading assembly '..\Debug\net40\bin\FSharp.ProjectSystem.FSharp.dll'

[vasily-kirichenko]

Error	FS3160	Problem reading assembly 'E:\github\visualfsharp\Debug\net40\bin\FSharp.ProjectSystem.FSharp.dll': Build was not evaluated, expected the results to be ready after 'Eval' (GetCheckResultsAndImplementationsForProject, data = ("FinalizeTypeCheck", [|Id 1070; Id 1071; Id 1072; Id 1073; Id 1074|], Id 1076,
 false, None)).	VisualFSharp.Unittests	E:\github\visualfsharp\vsintegration\tests\unittests\ServiceFormatting\TestHelpers.fs	1	Active

[dsyme]

I have seen this. Do you have a reliable repro?

[majocha]

I can repro this on current master by referencing a library in a console app.
Repro

[dsyme]

@majocha I tried opening Library3.sln but didn't reproduce this error.

• Could you write out step by step instructions please?

• Also indicate if you have in-memory-project-references on or off (it is on by default, see Text Editor --> F# --> Performance).

• Also indicate whether you have built the solution or not

@cartermp I've marked this as "fix now" since the above error should really never happen.

[majocha]

@dsyme Now I had problems myself, but I think I nailed it. It appears it happens for pre-opened files only.

Repro steps

1. current master build VisualFSharp, in-memory references enabled.
2. clone Repro, open solution
3. open Program.fs
4. close and reopen solution so the Program.fs gets auto loaded into editor

ETA: building the solution is not required, it builds fine, the error shows up when the file is pre-opened on solution load.

[abelbraaksma]

@majocha, @dsyme, the repro from the previous post works reliably (using current nightly, in my case, not necessarily the same as current master). And as he said, you need to have tabs open from your previous session to receive this error.

Also, rebuilding, clean etc does not remove the error. Closing/reopening the offended tab does not resolve it either. You can see it in this vid, using the above repro: