Note that we don't officially support Compressor, as we've received many problem reports, and some of them resurfaced with recent updates – therefore, we suggest exporting directly from FCP or Motion.
More specifically, due to bugs introduced in Final Cut Pro 10.4.9 (and later), and Apple Motion 5.4.6 (and later), the following actions may corrupt our plugins' registration in macOS:
Sending to Compressor (either from Final Cut or Motion),
Exporting MP4 from Motion,
Saving Motion projects with the "Save preview movie" option enabled.
To fix the issue, please reinstall affected plugins using mInstaller or the manual PKG installers that can be downloaded from your 'My Products' page (the download link will appear once you hover your cursor over the preview miniature): https://www.motionvfx.com/user/products
After that, avoid the aforementioned actions or the issue will reappear.
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. After that, export your projects by selecting the newly added destination in the Share menu instead of using the Send to Compressor command.