Hi,
Make sure that you have enough free space on your internal drive for iMovie to operate.
If you keep a Time Machine backup try restoring your iMovie library to a point in time before the data loss. Restore it to a different location so as not to overwrite your current library.
If you have no time machine backup, try going to the iMovie Backups folder to open an earlier saved backup of you current library.
To get to the iMovie Backups folder,follow this file path from the Finder menu:
Go/Home/Library/Containers/com.apple.iMovieApp/Data/Library/Caches/iMovieBackups
NOTE: If running Ventura or later, in the above
file path substitute iMovie for com.apple.iMovieApp. So, for Ventura,
the file path would read:
Go/Home/Library/Containers/iMovie/Data/Library/Caches/iMovieBackups
When you get there you will see a list of previous backups of your iMovie library. Click on one dated just before your issue started. iMovie will open in that library. Navigate to your projects browser (where your projects are displayed as icons) and see if your projects are intact.
-- Rich
