iMovie 3.0 introduces two new major features - storyboards and Magic Movie. Try to restore a previous version of the original library from a Time Machine or other backup.Apple is releasing an iMovie update today for iOS and iPadOS. If the new library and project work as expected, you've isolated the cause of your issue to the original library or project.

Try to recreate the issue you were having. For example, if iMovie quit when adding a transition, try to add a transition to the timeline.

Select the clip in the browser, then press the E key to add the clip to the timeline.Select the 'Finish Line.mov' file in the list, then click the Import Selected button. Choose File > Import Media, then click Desktop in the Import window sidebar.Click projects to return to the Projects view.Next, import the QuickTime video file into a new project in the new library: Choose File > Share > File, click Next, name the file 'Finish Line,' then save the video file to the Desktop.

Choose File > New Trailer, click the Action trailer template, then click Create.In iMovie, click Projects to return to the Projects view.Next, create the test project using a built-in trailer template, then export it as a QuickTime video file: Name the test library 'Test iMovie Library,' then save it to the Movies folder in your home folder.In the Open Library window, click New to create a new library.While you press and hold the Option key, click the iMovie app in the Dock or double-click the iMovie app in the Applications folder.You can create a new library and test project to check if the issue is with your library, project, or iMovie app.

How to update imovie on mac