Hi,
Just guessing, but it seems like the link between the iMovie app and the library is not working properly. Possibly that is being caused by a malfunctioning preference or maybe some corruption in your iMovie library. You can try some of procedures below to see if you can get it solved.
The first thing I would try, since it is easy to do, is to delete/reset preferences. Open iMovie while holding down the Option and Command keys and select to delete preferences in the box that appears. iMovie will open in a new empty library. Reopen your old library to get back to your projects. Now see if your media display is restored in iMovie. Possibly you may need to reboot to set the changes. Deleting preferences is a safe procedure that will not cause data loss or disruption to your project.
Another thing that you can try is to copy the media in your project's timeline into a newly created project. In your present project do Edit/Select All, then Edit/Copy and then open new project and Edit/Paste into new project. Your edits will carry over. See if the media displays properly there.
You might also try copying the project into a different or newly created library. Select or create a new library by doing a File/Open Library/New or Other. Then, from the projects browser screen, where your projects are displayed as icons select the project and do a File/Consolidate Project Media. Then, move your cursor over the project's icon to make a little circle with dots in it appear to the right of the title. Click on the circle. In the drop down menu that appears, click on Copy to Library and select the new or different library. The project will be copied to the new library. Open it there and see if works properly.
Another thing you can do is to open your present library in an earlier saved version that has automatically been saved to the iMovie Backups folder. 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. Accessing a backups library will not overwrite your current library.
-- Rich
