iMovie Compatibility

Try following the procedure below to get the highest version of iMovie that High Sierra can run. It requires that you have, or at one point in time did have, an earlier version of iMovie on your Mac.

To update/redownload iMovie 10, drag your iMovie 10 app from the Applications folder into the trash, but do not empty the trash. (You can skip that step if you had iMovie 10 on your computer before, but deleted it.) Sign in to the app store and open your purchases folder by clicking on your name at the bottom of the app store side bar. (NOTE: For El Capitan and older, click on the Purchases tab at the top of the app store screen and then sign in. Click on Purchases again to reveal your purchases.)  You

will see your purchases displayed, including iMovie 10. Redownload/update iMovie from there. If not successful, drag your present iMovie app out of the trash (if you moved it there) and return it to the Applications folder.

-- Rich

For those who have not previously acquired iMovie 10, Apple is only offering the current version downloads.

You might take a look at this thread that describes a way to get iMovie 10 from the iMovie 9.0.9 dmg. Pay particular attention to the post by spectre_ghost about half way through the thread.

https://discussions.apple.com/thread/251259186

-- Rich