I can never export my project, what's the problem?

For a long time my project has never been able to export, suddenly I am no longer able to export, even though I have not modified the project much.

Is there a solution? Knowing that I did not leave a solution available on the Internet without doing it, and I also copied the project and the same problem still exists.

It looks like your project is corrupted
Import your latest backup and restart from there


I’ll try that, even though the backup is relatively old, but it’s better than starting from scratch
Thank you very much