[X# 3] Build does not start after opening VS

[hpetriffer]

If I open VS2026 and I want to build the solution I get the message "Build started at 09:47..." in the output pane. After that nothing happens. If I close VS than I get a message that the build is in progress. After that the build starts really and I get new messages in the output pane. This problems seems to happen always.
The last time I got also the following error (first time)