Hotfix for saving projects.
It's essential to keep backups of any important digital work you do. If you have made backups then you need to find one of your backups and restore it. If you have not made any backups or set up Construct to make backups for you, then I'm afraid there isn't any way to recover a lost local file save - unfortunately this may be a hard lesson in the importance of keeping backups.
I understand, Thanks.