If you are having issues with Firefox freezing, please try to reset firefox Refresh Firefox - reset add-ons and settings

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

If it works in Safe Mode and in normal mode with all extensions (Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: Firefox > Quit Firefox; Linux: Firefox/File > Quit)

• If you have many extensions then first enable half of the extensions to test which half has the problem.
• Continue to divide the bad half that still has the issue until you find which one is causing it.

I have a problem with one site that locks up Firefox and I want to shut down that tab WITHOUT closing Firefox.

If Firefox is locked in such a way that you can't close that tab via normal means like a middle-click on that tab of via its close button or the keyboard (Ctrl+W) then your only option is to kill Firefox via the Task Manager.

I have this problem too. I close all the tabs and close Firefox. Then when I open Firefox again all the tabs (now around 10) appear. If I go to File on Firefox and click on close Firefox they still reappear. What a nightmare - the slow my computer down. Do I need a different Browser or is there and answer to this Problem?

Hi rebeccaspeer10, you posted the same comment in 3 different threads. I replied here: https://support.mozilla.org/en-US/questions/966344#answer-504910