TooMany Tabs. All rows and tabs have suddenly disappeared.

Firefox add on TooManyTabs was synchronised on 2 machines, Vista and
Windows 7.
Suddenly all toolbar rows and tabs disappeared.
All that is left is what beginners find - 6 rows of empty files
in toolbar and in Bookmarks Sidebar - TooManyTabs (do not remove).
Can anyone help please with retrieving the missing rows and tabs.
I had more than 10 rows consisting of more than 20 tabs each.
Thanks.

 

Many thanks.
Will check those out and let you know how it goes.

 

Solution to problem is;

Bookmarks > Show All Bookmarks > Import and Backup > Restore > Choose Date From
Which To Restore.

Hope this might help someone else.

Thanks for your help.