Update: Just tried running C9.5.10 in Win 8-compatible mode and so far it hasn’t crashed. I tried the thing that would reproduce the issue every time and it didn’t freeze. I will do some more work with Cubase today and drop an update later. Stay tuned.
The only thing so far is that the eLicencer complains about not having all the administrative rights it claims when starting Cubase. Still; the DAW opens fine.