major error opening project

Hello’ i have Cubase 9 Pro with dongle and i have 2 projects suddenly can’t be open.
ERROR MESSAGE: "invalid project file “BLACK HOLES_FINAL.cpr”!
And now it turned into a new error after i have reinstalled Cubase with latest update 9.0.4:
“Project BLACK HOLES_FINAL.cpr was created with Cubase version 9.0.0 this program version cannot load it”

My BAK files also missing from the folder and no where to be found.

i’m in mastering stages and it’s a MEGA drama with my client!!!

PLEASE HELP!!!

Hard to say what went wrong from the info given. Hopefully, you have been backing up your projects externally. If there are no .bak files in the project folder autosave was probably not active.

@steve Autosave was on (and still on), creating every 30 seconds 1 BAK file. It has been like that for the past two years and i never had a problem. i have this project backup but as consolidated tracks. I just need access to the midi tracks for a few modifications but then this happened. Real bummer !

Yeah, bummer…

Steinberg team has requested the CPR files of the projects, they managed to open one project, they saved it in new name and sent it to me, works like a charm. the other one is dead i guess, i also tried to open it with CB 5…nothing’ same error. I only need to access it for midi track modification…Bummer #2