Recover user data
Newest version of Firefox created extreme issues with my iMac. Did everything possible to try and remedy slow opening, crashes, freezes, etc so I used TimeMachine and installed previous Firefox version but in process I lost all my bookmarks, etc. Firefox created folder of old user data and placed it on desktop called: Old Firefox Data. However, everytime I go through process of trying to reinstall it via Firefox help page under Profile, all I get pulled up to reinstall is Safari or Chrome. How do I get Firefox to pick up Old Data File?
What kind of issues did you encounter when you updated to Firefox 94 ? Note that Firefox 94.0.1 has some fixes for Mac.
You can check the compatibility.ini file in a profile to see what Firefox version last used the profile. Downgrading a profile is not advised as files and folders might have been upgraded to a newer schema making them incompatible and possibly get data loss with a next update, so using a Firefox 94 profile with Firefox 93 is rejected.
Firefox 67 and newer use a dedicated profile for each Firefox installation and lock this profile to prevent other Firefox installations from using this profile.