What version of iMovie is compatible with… - Apple Community
: Enhanced stability when updating video libraries and projects created in much older versions of iMovie (such as iMovie 9). Audio Bug Fix
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Version 10.1.6 is highly sought after because it is one of the last stable versions compatible with older hardware before Apple shifted requirements toward Big Sur and Monterey. It improved library stability and fixed volume issues that occurred after clip transitions. How to Get iMovie 10.1.6 (or the Latest Compatible Version)
: Acts as the "end of the road" for users on OS X El Capitan (10.11) and High Sierra (10.13), as later versions like 10.1.14 require Mojave (10.14) or newer. How to Download for Free