After restarting Firefox, all tabs previously sorted in many groups are in Ungrouped. All informations about tabs in groups are lost. Sorting tabs into groups has already been specified for add-on. There is no situation for the add-on to lose this information. Add-on has poor session management and is unreliable. It is very frustrating for the user to reorder all tabs into groups again and again...

After some time, about 80% of the pages on other tabs were lost. The plugin has **absolutely unreliable** status information management.