: Users reported significant slowdowns in import times—sometimes jumping from minutes to over an hour—and frequent "Can't Encode" errors during export.
For users on macOS High Sierra, was a mandatory update to ensure media compatibility with newer iPhones. However, for those with older hardware or a preference for the iMovie 9 workflow, it felt like a downgrade in efficiency. iMovie 10.1.9
: Resolved critical issues where HEVC video clips and HEIF photos would incorrectly appear black in the viewer. Bug Fixes : : Resolved critical issues where HEVC video clips
: Built on the foundations of the 10.1 branch, this version continued to offer accessible 4K editing (3840x2160) for compatible Macs. iMovie 10.1.9
The primary focus of this version was compatibility with the contemporary hardware and media of the time:
Despite the bug fixes, many veteran users remained critical of the version 10 architecture: