Invalid Project File Cubase Pro 11

Is there a fix for invalid Project File error message? I’m using Cubase 11 Pro on a Mac OS Mojave.
I have some projects that were done on Cubase 8, some open and some don’t. This happened I believe after I migrated to a new HD and to a newer Mac Pro.
Any help or suggestions would be greatly appreciated!


Could you be more specific, please?

What does it mean, the project doesn’t open ? Any message? If yes, when does the message appear, please?