After a windows update my computer decided I was on a trial version of windows and made a mess of a lot of things. Not a problem I thought as I had everthing backed up, including firefox and thunderbird (on 78.1.0) both as mozbackup files and by copying the contents of the profile folders. Thats the background, now the problem. Thunderbird refused to recognise my mozbackup restore. Not a problem I though I'll just copy my thunderbird 78.1.0 profile into the 78.1.0 profile on my restored ssd. It doesn't work. Thunderbird won't read its own profile! This is very frustrating and I can't see a way round this, any help would be gratefully received as I'm dealing with emails over the last ten years David