I assume that the crashing is happening with all of your projects. If you have not tried opening more than one project, try some others to rule out corruption that might be confined to just one project.
If the crashing is global, here are five procedures that you can try to address issue:
- 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 library. Reopen your old library to get back to your projects. Now see if the crashing issue is solved.
2.If still no luck, try booting up in Safe Mode (see Finder help menu for instructions) and as soon as everything loads immediately shut down and restart in normal mode. Sometimes that clears out conflicts that cause crashes.
3.If the problem persists, try opening iMovie in a new library by opening iMovie while holding down the Option key and, in the box that appears, choose a different library or create a new library. See if that works. If you create a new library populate it with a project or two to test.
4.Try opening iMovie in a new user account, either one you create or by using the Guest account on your Mac. See if iMovie works properly there.
5.All else failing, try redownloading iMovie from the online app store. To do that, move your current iMovie app from the Applications folder to the trash, but do not empty the trash. Then go to the app store, sign in, and navigate to your Purchases folder and redownload iMovie. If for some reason you can't get a new download, move your old iMovie app from the trash to the Applications folder.
-- Rich