Due to bugs introduced in the recent versions of Final Cut Pro (10.4.9 or newer) and Apple Motion (5.4.6 or newer), the following actions may corrupt our plugins' registration in macOS:
Sending to Compressor (either from Final Cut Pro or Motion),
Exporting MP4 from Motion,
Saving Motion projects with the “Save preview movie” option enabled.
To resolve the issue, please uninstall products through mInstaller and install it anew.
Note that we don't officially support Compressor as we've received many problem reports and some of them resurfaced with recent FCP/Motion updates – therefore, we suggest exporting directly from FCP or Motion. If you need to use Compressor, there's a workaround for FCP (not for Motion, though): open the File > Share > Add Destination dialog and add a Compressor Settings destination. Thereafter, export your projects by selecting the newly added destination in the Share menu instead of using the Send to Compressor command.
If you depend on Compressor, be sure to report this bug to Apple via their feedback page: