Bizarre solution to crashing issue

I’m wondering if someone could shed some light on this phenomenon I’m experiencing.

I started working on a project in Cubase 9.5.41. I moved to Cubase 10 and continued to work on the project for 3 - 4 weeks. Initially the project loaded up with no problems but then, as other have reported, I started to experience the ‘poof-style’ crash upon loading the project. A workaround I discovered was to first load an empty project, then load the desired project without activating it, and then manually activating the project. It would still crash 1 - 2 times but would eventually load. I persevered with using Cubase 10 but I also found that everything was exceptionally laggy. The key commands setup window took like 30 seconds to load (as opposed to 2 seconds on Cubase 9.5). Opening up the lower zone and key editors was also extremely sluggish, Cubase would freeze for a couple seconds when switching between different active parts in the key editor, and auto-save times on this project went up to 10s (compared with 1-2s on Cubase 9.5). A complete nightmare. I tried trashing prefs but all of the sluggishness was still there.

So then I switched back to 9.5 after discovering that Cubase supports forward compatibility. The project worked fine in 9.5 and all the sluggishness had completely disappeared. Everything was snappy. However the project, which was fine before moving to Cubase 10, was now crashing on load in Cubase 9.5 and I could only open it using the workaround posted above. At first I thought perhaps the project had been somehow corrupted by Cubase 10. However, by some miracle I stumbled upon post on these forums claiming that 90% of the problems in Cubase 10 could be resolved by uninstalling 9.5. So i’ve just tried the opposite - uninstalling Cubase 10 - and lo and behold the project loads first time, reliably, with no crashing.

What’s going on here? Are there any possible explanations for why this is the case?

I’m considering reinstalling Cubase 10 and uninstalling Cubase 9.5 to see if it really was just a problem with the two versions existing side by side, but I’m kind of exhausted with all the issue hunting, preference trashing and rebuilding. So I’m going to stick with 9.5 for now.


Could you attach the crash please? Then we could know more.