Verify that this is a live Construct 3 project consisting of a single file (.c3p).

Today I could not open my project! In version r317-2

FAILED TO OPEN PROJECT. CHECK IT IS A VALID CONSTRUCT 3 SINGLE-FILE (.C3P) PROJECT

Please help me, I didn't save any backups, everything was stored on google drive

I found this message in the console:

Try opening it in the latest release of Construct (r327.2).

haliluya! Thank you very much everything worked!))