Thanks for helping Martin,
I decided to upgrade to Cubase 10.5 because of this problem I had with Cubase 9. Ironically, as soon as I installed Cubase 10.5, all of a sudden Cubase 9 started to work again. I didn’t uninstall ReWire, it is still there, and both versions work ok.
May I ask you one more thing about Cubase 10.5? Looks like there is some incompatibilities with VST3 plug-ins. I have Omnisphere in the blacklisted plug-ins and the reason for Cubase is “unknown”. Can you give me any advice on how to make it recognise Omnisphere again. Or do I have to open a new thread in the forum?