I just had to force quit a hung IDE (windows 7, Xojo 20015r2) and after restarting received the “Unsaved changes were found do you want to restore” dialog. I hadn’t made any changes to my project so I said no. When the IDE loaded up my project was gone from my drive.
I’ve tried to reproduce by creating a new project, making some changes, running it and then using Task Manager to end the Xojo process. I get the dialog and select no but have been unable to reproduce the project going missing.
Just a warning. It may be safer to say yes and then open the original project rather than saying no.