Hi, there could be a number of reasons for that, but first hold down the Shift key when you start Firefox to start in Safe Mode. More - [[Troubleshoot Firefox issues using Safe Mode]]. If it works in Safe Mode, restart Firefox, then disable any theme or extensions you have - 3-bar menu > Add-ons > Themes/Extensions and restart Firefox again; now if it's OK, re-enable them one by one until you find the culprit. You may need to restart Firefox after enabling some extensions. ---------------------------------- If that doesn't help, please see [[Firefox hangs or is not responding - How to fix]] ''If your question is resolved by this or another answer, please help other users by marking the best reply as Solved. Thank you!''