This is common with apps not downloaded from the App Store. To bypass:
Searching for "iMovie 10.2.5 DMG" often leads to unofficial sites like FileHippo or MacUpdate . imovie 10.2.5 dmg download
If you have landed on this page searching for an , you are likely facing one of two scenarios: you are running an older Mac that cannot support the newest iMovie versions, or you prefer the stability and specific feature set of this particular release. This article will provide everything you need to know—from where to find a legitimate DMG file, how to install it, what features to expect, and why this version remains relevant today. This is common with apps not downloaded from the App Store
: Click your name or icon at the bottom-left sidebar. how to install it