After "Relaunch in Windows 8 style Firefox" I lost my tabs / group tabs !!!
Having some pinned tabs, normal tabs, and more tabs divided in tab groups, I clicked on "Relaunch in Windows 8 style Firefox". I couldn't view my tabs in the new interface, and I tried to create a new tab and open a page. After that I clicked the option to return to the desktop version.
Firefox desktop started with blank tab, I can't get any of my session tabs. I can't restore the session neither last closed windows.
Is it possible to recover it? It was a bad loss!