Everything I have done today is gone. 2 hours of work is ruined!
All saved Cubase projects says:
"Project “xxx.cpr” was created with Cubase 1.x.
This program version cannot load it. " Whatta hell now?
Cubase, Monterey, plugins all latest version.
No information, no help.
What do you need?
What Cubase version are you using ? I guess that it’s a recent one. At first glance, I would try to install SX3, then load and save the project again with it. Normally, it then should be usable by all the Cubase versions that were published after : see here, for more details…
But what is strange, though, is that normally a SX1 .cpr project file should be directly compatible with SX3 and further versions, contrarily to an .arr one. So, still something to try, I think, but without being sure of a successful result…
Yes. all SW versions are current. I added to my profile.
Strange problem indeed. How Cubase 12.0.40 can even save file that itself can not open is mystery.
I first thought its all gone, but I remembered all I had done in few hours and I quickly got back up to speed from yesterdays song version.
Good idea to try SX!
Thank you very much cubic13
Glad that you got it sorted, somehow…
Additionaly, I would be sure to save the involved projects with a slightly different name to force Cubase to create new .cpr files, which will surely be compatible, unless there is a mysterious voodoo process going on…
Yes. That is how I have been saving project versions since SX days. That’s good advice when working with Cubase.
This means that your project is corrupted. Cubase can see that it’s a supposedly valid .cpr file, but it can’t load it.
This is not going to help. Cubase SX wont be able to load it either.
Point taken : his project is corrupted and I can just hope that @Takkyi has a safe backup of it somewhere.
I would like you to note that I did a warning about my own suggestion, though. Maybe you haven’t read it until its end, so, I invite you to read it again…
There is a menu entry and a key command (Strg+Alt+S) available to save a current project as a new version, and Cubase/Nuendo adds a two-digit number at the end.
So you have a basic version control at hand.
Yep. It’s another way to do so… 
Thanks for everyone. I got it sorted. I restored from Time Machine backup and rest from my head 
Something went bonkers in Cubase. From start of the day all saved versions including .bak files was corrupted. I noticed that after Cubase just disappeared without any crash logs and I tried to start project again.
This kind of things erodes trust for Cubase. That nagging feeling, if this gonna happend again… I prefer and like very much Cubase way of workflow over LogicProX even Im fluent with it.