When I open anki, (I downloaded the new version on my mac), I receive the message that anki encountered a problem with Synapse Pro- Ultimate Anki Workspace.
Basically add-ons are developed by individual volunteers and are not supported by the Anki community or the official Anki, so if you encounter a problem with Synapse Pro you’ll need to contact the author via the add-on page. If an error is displayed click the “Copy Debug Info” button to copy the info and send it to the author this will help their development.