Hold down the Option + Command keys while opening iMovie. A prompt will ask if you want to delete the app preferences. Click Delete Preferences . This resets the app without deleting your video projects. Final Verdict
If you have downloaded it before, you can download the latest version (which is often 10.3.x) and upgrade. 2. Alternative Method (Legacy/Archive) imovie 10.3.3 dmg
You will find many websites offering a downloadable "iMovie 10.3.3.dmg" file. You should never download iMovie from unofficial third-party websites or torrents . These files can be unsafe and may contain malware or other harmful software. Always get your software directly from the official Mac App Store. Hold down the Option + Command keys while opening iMovie
Released as part of Apple's continuous deployment cycle for macOS, iMovie 10.3.3 is a stable production build of Apple’s entry-level video editing software. This specific version focused on stability improvements, performance optimizations for Apple Silicon (M1/M2 chips), and deeper integration with projects imported from iMovie for iOS and iPadOS. This resets the app without deleting your video projects