After installing Groove Agent 2, Live did not want to start anymore - it came up an error message "Folder removed" and than Live crashed.
As it turned out, the install process of GA2 (or the necessary Steinberg "License Control Center") changed the access rights of some of the VST Plug-In Preset folders to "read only".
I had to log in as root to change this, the normal procedures did not work.
Hope this helps others with similar issues
hginfo