Cubase 9.5 hangs on project close on Win 10

I tried to uninstall and reinstall interface driver, midi controller driver, some plugins - still the transparent insert effects. but then without
any obvious reason when i restarted it another time the insert effect colour appeared again. and today… it´s again gone (see screenshot).
when i load the plugins they look normal tough. i don´t know if there are other changes to cubase 10 as i didn´t work for long with these transparent insert effects.
is it possible to move this topic to another category - as it is no longer about cubase 9.5 hanging?