“DITTO! If a plug-in refuses to be ‘re-activated’, there should be some sort of Reason Code or Log.”
If a plug-in refuses to be re-activated this usually means on Windows that the dll is not a valid plugin dll. IZotope for example installs dlls into the VST Plugin folder that are no valid plugins. The scanner sorts them out.
All iZotope plugins should be available in Cubase on Windows.