I have spent more than a day on this, nearly two really - pulling plugins away - swapping this preference file with that - and eventually I seem to have managed to get it to play ball, although I’m somewhat afraid to breathe on it right now in case it all falls over again…
I’m not looking forward to opening old projects.
But just by way of hopefully some sort of answer to this:
I parked ALL the VSTs that were not either 64bit or VST3 somewhere safe and ran it up again.
Still not happy.
I then went for a complete brand new install of 10.5 [without having my previous versions going back to 7.5 still on the system]
So this was on as clean a system as I could muster, before adding things back in, and then scanning VST plugins bit by bit and trashing the ones that are obsolete
It definitely seems old plugins are likely to be to blame for much of this - bu I don’t think all, well not in my case anyway.
Pref files and things like mixer settings and controller settings (I do use a 16 channel Presonus thing) and keyboard shortcuts were a nightmare to correct.
Steinberg seemingly do not make these easy to find or collate. It’s not just one Cubase pref file but several.
And the Default.xml file was a serious issue - I could not use my previous version without it crashing around my ears.
Melodyne issues abounded too , which they never have before. I was prepared to ditch my Melodyne singletrack - but because I read that Cubase and Melodyne now interact I just did another fresh install of it and tried again.
All this started because I dicovered that with High Sierra
- I could not open two instance of various Izotope windows without a crash [and was told by support that this was an incompatibility with High Sierra]
- Some plugins [notably Waves Soundshifter, Zynaptic plugs and Oeksound Soothe - but some others too] always crashed the system with a large project (which all mine are - being mostly orchestral with VEPro7 attached.]
- Occassional graphics freezes and WindowServer hangs were becoming somewhat frequent.
Of course annoyingly Apple don’t make it easy to go to something like Mojave anymore - so my options were either to persevere with Catalina OR Carbon Copy restoration of my previous system - which would more than likely not be trouble-free!
Touch wood - I think we’re on the home straight now.