After a system crash i decided definitely to say bye bye to windows 7 and to upgrade cubase to 10.5 from 9.0.40.
Now i have a dilemma about my studio work.
It’s a personal studio and when crash happened i was in the middle of mixing a huge personal work that i started years ago (as you can imagine music is not my primary work…).
So the question is: did you suggest to continue mixing with cubase 9.0.40 or to proceed with one of the upgrades (9.5, 10, 10.5)?
I would like to use some of new features but i don’t know if the new releases are risky about possible compatibility issues with 9.0.40 files.
Wich new versione is safer from that point of view?
Thanks for your help!
It could be a can of worms due to subtile differences in sound. Installing 9 for your older projects next to the latest version is no problem.
In addition you can open files created in C10 with C9 - of course non-existent features won’t show up, but they will still be there when you open it again in C10.
I typically do a Save As in C9 and name it something like “CoolSong-C9 version.cpr” Then I can open the original version in C10 and continue on with the assurance that the old C9 version is available if needed. 
Thanks for both usefull suggestions.
But now you have inspired to me two more question:
Regarding settings transfer, it’s ok to install only 10.5 next to the 9.0?
I’m curious about the “subtile differences in sound” of 10.5 vs 9.0: where these come from?
Thanks again fro your help!
Each major version (X.0 and X.5) is always a completely separate instillation. So it is fine to have several installed next to each other. In fact you can even have both open with different Projects at the same time. Currently I have 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 and 10.5. Mostly because uninstalling them requires some effort and leaving them there doesn’t hurt anything. They will get trimmed back when the PC is replaced.
If you just have an audio file in both 9.0 & 10.5 that isn’t being processed or run through plug-ins I’d expect them to produce the exact same output. The audio engine hasn’t been changed.
Regarding transferring your Settings, that is supposed to always occur. But you will find folks on here where that didn’t occur for some reason that isn’t fully understood. The fix is to just copy the missed file(s) from the 9.0 folder to the 10.5 folder.