[oblio]

> The same issue appears already with JetBrains Rider (a C# IDE where the C# parser is implemented in a separate process)

The fact that Resharper (which powers the Rider language processing bits) blocks the VS UI should tell you that this problem lies elsewhere.

[kuschku]

Resharper is out-of-process nowadays, afaik. Even in VS.

[oblio]

Then definitely that should raise some alarm flags. Why would an out-of-process server block the VS UI, unless there's some other problem?