when I press F1 - and click on Arduino Board Manager nothing happens.

other points of context:

1. F1 - Select Serial Port works fine.

2. when I start Visual Studio Code I see the following in the Output tab:

      [Starting] Update package index files...
      dummy
      [Error] Exit with code=undefined
   

3. if in the Terminal tab I enter:
   & "C:\Program Files\Arduino IDE\resources\app\lib\backend\resources\arduino-cli.exe" core update-index
   I see:
   Downloading index: package_index.tar.bz2 downloaded
   but that is it