User Agent: Mozilla/5.0 (Ubuntu; X11; Linux x86_64; rv:9.0.1) Gecko/20100101 Firefox/9.0.1 Build ID: 20111221233052 Steps to reproduce: when clicking on the Tab Groups button, nothing happens Actual results: nothing Expected results: tab groups screen should have been displayed
this happens occasionally
This bug has not occurred recently, although there have been other minor problems. As it was okay in Safe Mode, I decided to track down what might be causing the problems, and disabled some plugins. Specifically I found that Firefox worked better after disabling the following: DivX Web Player plugin QuickTime plugin Silverlight plugin VLC Multimedia plugin Windows Media Player plugin
Do you have any extensions installed and enabled in the Extensions pane of the Add-ons manager? Can you catch the specific add-on that might cause the button not to work? That is if you can still reliably reproduce this issue.
Closing for now, please comment if you have more information to provide.