Hi Jan,
Thank You for reporting it and happy birthday! I think that you hit the corner case issue that your python tools couldn’t be updated correctly. It was most likely due to Python process for program debugging still running on your system in the background. I recommend restarting your PC and then reinstalling Studio. After uninstalling you can also make sure that mbed-studio-tools folder is fully uninstalled. It will be in ~\AppData\Local\Mbed Studio folder for current user installation.
We will look closer at pyOCD not closing correctly on Windows and will try to fix it.
Thanks,
Arek - Mbed Studio team