Hi Atom7, sorry to hear about this problem.

If you haven't already, could you close out of Firefox and do a normal Mac OS shutdown and restart to complete any pending updates and release any file locks.

The next time you start Firefox, check whether you can get back to your earlier settings/data by switching to a different profile, as follows:

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have any other profile(s) listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, back on the about:profiles page, click the Set as default profile button for that profile so Firefox uses it automatically at the next startup.

Any progress so far?

thank you, thank you, thank you! i'm so sorry it's taken me so long to get back to you. yes, that worked absolutely brilliantly, and i now have all my settings again. sorry again for lateness.

Glad to hear you solved it. Thank you for reporting back.