I've been using OneTab, it was great until I've lost all the tabs (300+ of them) suddenly. I'm not entirely sure why this happenned, my FireFox is version 48.02 as I haven't been able to update it since my Mac OS has become outdated. Maybe the OneTab has become too new for my browser? I now see the "file not found" page on my OneTab tab, and I can no longer see the icon of OneTab either on the toolbar or in the list of add on-s...