Hello again sundqjan:
I uninstalled the files using the 10.0.30 updater (like you, in the second round were all gone), with exception of the main application Cubase. Then I copied the full Cubase 10.0.30 installer (circa 20GB) to a folder C:\cubase_inst and used it to install all again (without uninstalling all my external VTS and VSTi). The missing files of Groove Agent are now in the same folders that you have in your system. Here Cubase found them automatically, so all ran flawless. And not only that: before, when I clicked on GA -load kit and then -All Instrument Sets, all images of my sets were covered by a shadow. Now I can see all images of my installed GA Instrument sets.
Thank you for posting your experience!
And mr.roos: I must confess that I didn’t know about the Steinberg Library. Indeed, it is installed in my system and I can see clearly where all files are installed in my system. I noted that they can be moved, too. Thank you.
Regards.