FIXED::::Latest 10.5.1 Hotfix bombed my Cubase. Please Help.FIXED

Ok, I am reasonably fastidious when updating Cubase, having suffered at points in the past.

On installing the Upgrade (not the full app - shame on me) Cubase will NOT open - it crashes during loading. just after loading Media Bay.
So I downloaded the full 10.5.1 and installed that (after deleting the current non working one) = SAME THING - not loading.
So I deleted my prefs = SAME thing.
So I deleted it all, and went back to 10, the last I saved on another hard drive. = SAME THING - bombs out after Media bay load on the splash screen - somewhere around load media bay and ara on the splash screen.

Please - what can I do?
I now have no cubase.
something has affected it all.
I am pretty much thinking that this is it for me. Too much headache - but I want to fix this - need to really.

Any help appreciated.
T xx
Screen Shot 2020-02-20 at 6.32.00 pm.png

Hi,

Delete Cubase 10.5 from your Application folder. Delete Cubase 10.5 Preferences from the Preferences folder.

Download Cubase 10.5 Full Installer and install. If Cubase still crashes, rename Cubase 10, or even Cubase 9.5, Cubase 9 preferences folder. Start Cubase 10.5.

If it still doesn’t start, shar the *.crash file, please.

Thanks for all of that Martin. I had pretty much taken it back to a naked instalation, and found the issue to be a vst3 plugin, by adding my plugins bit by bit and waiting for it to fail - it did with my Melodyne vst3. No Idea why this should be, but it is now running. Will re-install melodyne at some point. But I have had enough of the problems with Cubase for now. Never as solid as logic, PT, Reaper. Bit I adore cubase. Much thinking to do.
Thanks,T
Xxx

Make sure your Melodyne is version 4.2.4.001