[design-time only] Assembly reference was not found or is invalid

[0x53A]

This is only an issue at design time, build is ok.

The file exists on disk, and was built by a different (C#) project in the same solution.

[dsyme]

@0x53A We'll need a step-by-step repro for this. Does rebuilding the project succeed?

It could also be a manifestation of #3047

[0x53A]

@dsyme Yeah, thats the great thing about this and #3054 (comment), it's not reproducible in a small isolated project.

Build and Rebuild work fine, but do not clear the error.

[0x53A]

I have this and #3054 (comment) in a base-lib which depends on 5 other projects. If I remove everything except these five projects from the solution, then the error stops happening, even though there should be no change from the view of these projects.

For me it looks like something completely unrelated in the solution fucks VS up.

The whole solution has ~60 projects, so I'm not going to try all permutations and check which of these causes this.

For now I'm dropping VS and using Rider, not because of this bug, but because of #3054 (comment), which now happens always.

[dsyme]

Build and Rebuild work fine, but do not clear the error.

Did you check if switching between "Build" and "Build + Intellisense" clears the error?

Re #3054 (comment) it feels likes this should be tracked by a separate bug.

[0x53A]

Did you check if switching between "Build" and "Build + Intellisense" clears the error?

Yes and No. It is visible in the "Error List" for either "Intellisense Only" or "Build+IntelliSense", but is always visible as a red squiggle in the document at location (0,0). Switching does not affect the squiggle in the document.

---

My previous remark

The file exists on disk, and was built by a different (C#) project in the same solution.

is not completely true: when VS was started, the file did not yet exist (if the solution was built before opening, I hit #3222), but building the project does not clear the squiggle.

[plainionist]

hi,

seems I have similar (same?) use with my project here: https://github.com/plainionist/Plainion.Windows revision 0af9a48.
i tried endless things of clean + rebuild, changing .net version, updating fsharp.core .... the only "workaround" which i was able to apply successfully after several reopens of VS was to unload the fsharp project again and reload it after 2-4 seconds. (i have only one fsharp project among 3 c# ones).

hope that helps ...

regards,
seb

[dsyme]

@plainionist OK, thanks, we will try your repro