Thunderbird decided to update on it's own. The end result is that all all address books (of which I had about a dozen of) are empty. I went to check the appdata roaming thunderbird profiles -folder as suggested by a few others having similar issues. There are 40+ abook.mab.bak files of different numbers, each with a *.bak copy next to it. The baks are 4kB, the mab files are 320kB and needless to say, none of them contain any of the address books. Same with history files. There are no larger files to be found anywhere in that folder.

Does this mean Thunderbird decided to destroy over a decade's worth of work just to update the stupid software? *that* folder was not backed up. It also seems there are no previous versions of that file available, as usual with Windows. :/