Half of iMovie Clip showing black.
I am making a project in iMovie, and the first clip in it, the second half shows up black. I’ve been restarting my computer and and reopening iMovie, but it still isn’t working.
iMac 21.5″, macOS 14.5
Try opening the clip in QuickTime Player.
If it's OK you will know that iMovie is to blame.
If so, shut down iMovie then hold down the Option and Command keys as you launch it until a window appears asking if you want to delete the preferences.
Click the Delete Preferences button.