FWIW I wanted to add a comment that we recently ran into the same issue where the developer importing FMOD (v2.02.04 on Windows 10, Unity 2020.3.30f1) had no problem opening the project, even after doing a full library re-import as well as branch switching and Git clean as a sanity check, whereas two other Unity developers (also on Windows 10) were presented with the repair error upon opening the project.
Our current workaround is simply to delete the Mac lib folder as we aren’t going to be targeting Mac OS for our project but I’m curious to know if anyone figured out the actual cause of this issue.
Kind regards,
Duane