Very jealous reading all the comments as I can’t participate, updated to Cubase 10 back in June still not working (was traveling a lot). It will not install (and believe me I’ve tried, comes up for a moment then gone, cant even write in ID number) and I had no problems with Cubase 9 but its gone, its been overwritten. I’ve been using Cubase for years and very sad to have to go to another DAW but this looks to be the case, dont have time for any more of this, I just wish I had never tried to go to 10.
If I were you I would call Steinberg.
You can download Cubase 9 via Steinberg Download Assistant and install it again, of course! With your Cubase 10 license you can run any prior Cubase version.
Cubase 10 installation does not overwrite earlier versions. If Cubase 9 has gone there is another cause.
As for the ID number, if you mean the activation code, you don’t write that in Cubase anyway, it goes into the eLicenser.
Yes, Installing Cubase 10 will not overwrite earlier versions.
Most people in here will actually keep the old version for while after installing a new version, just to make sure that every ongoing project are still working.