The addons issue is caused by a certificate problem, Mozilla is tracking the bug here: https://bugzilla.mozilla.org/show_bug.cgi?id=1548973. Rolling back won't solve the problem right now, and after the fix, you won't need a rollback.

Thank you for your reply I did see the note on Mozilla concerning the certificate error and wondered if this was the issue Unfortunately I do not have the luxury of time because I am wishing to use a business machine and I have tasks to be undertaken immediately If rolling back will not solve the problem then I guess I will have to use another browser, which is a great shame as I always enjoyed Firefox Probably try Opera rather than Edge or Chrome Thank you for your reply, at least I know where I stand Regards TW

switching back to an older version won't help, as the issue is caused by an expired certificate. mozilla is already rolling out a hotfix, which should reach affected installations in the coming hours...

Hi phillip, thanks for your reply, I got that from the first response so had to move on and already switched over to Edge (and currently struggling to find where it keeps everything!)

Probably try Firefox again in the future

Thanks for your help though, much appreciated Regards TW