You are trying to install a newer version onto an old OS, or vice versa. Ensure your macOS is exactly 10.15.7 or 11.x. If you are on High Sierra (10.13) or Mojave (10.14), the last compatible version is iMovie 10.13.x, not 10.15.7.
Note: Apple does not officially support downloading legacy versions via VPP for more than two years after an OS release. Act quickly. imovie 10.15.7 download
Open the App Store application on your Mac. Search for "iMovie." You are trying to install a newer version
Click . This will automatically fetch iMovie 10.15.7 (or the nearest minor build, such as 10.15.6 or 10.15.8, depending on your specific OS build). Note: Apple does not officially support downloading legacy
The is not a simple Google search—it is a process governed by Apple’s legacy software logic. While it is frustrating that Apple hides older versions, the "Last Compatible Version" feature ensures you get a stable, signed, malware-free installer.
For those on newer hardware, however, consider upgrading your OS to access the latest iMovie features. Legacy software is useful, but modern security patches and real-time 4K playback are worth the upgrade.