I worked for about 3 days on the project (an Instagram post with 1080x1080px resolution/1:1) and everything went smooth.
Today in the morning after exporting the video to a lower resolution (720x720px) I returned 'back to edit' to find my project file completely messed up.
- music beat markers where gone
- most video clips from the timeline gone, together with pan/zoom and color enhancement infos
- position of the music and sound tracks displaced
Only to show some of the 'changes' in the project
This happened for me the second time in a project. Fortunately this time I was able to restore the project from an automatically created backup file.
I can therefore only recommend to everyone to set the auto save interval as short as possible and perhaps also to take these autosaved files into account for the backup.
Edit > preferences > Project > 'Auto save project every:'
Best regards
Andreas