[ubuntu] firefox sync

I get so frustrated with Firefox I never have a problem with chrome syncing but I just can't get FF to do the same. I have validated an account using FF on ubuntu. I can log in correctly with that system and everything looks good. However, if I go to any other system and attempt to sync I get the informative error "unexpected error" when trying to log in . I have used a clean Virtualbox FF, WIN7, WIN10 etc. but nothing works.

Has anyone made this work using *ubuntu as the prime system?