Hello! Let's see if a refresh can fix this for you!

The Refresh feature (called "Reset" in older Firefox versions) can fix many issues by restoring Firefox to its factory default state while saving your bookmarks, history, passwords, cookies, and other essential information.

Note: When you use this feature, you will lose any extensions, toolbar customizations, and some preferences. See the Refresh Firefox - reset add-ons and settings article for more information.

To Refresh Firefox:

1. Open the Troubleshooting Information page using one of these methods:
   • Click the menu button , click help and select Troubleshooting Information. A new tab containing your troubleshooting information should open.
   • If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.
2. At the top right corner of the page, you should see a button that says "Refresh Firefox" ("Reset Firefox" in older Firefox versions). Click on it.
3. Firefox will close. After the refresh process is completed, Firefox will show a window with the information that is imported.
4. Click Finish and Firefox will reopen.

Did this fix the problem? Please report back to us!

Thank you.

Refreshing Firefox {web link} is a LAST RESORT ! !

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding

https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster

https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix

https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram

https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding

MkII, I've tried refreshing. I also installed the latest version of FF: Quantum.

FredMcD,

Starting FF in Safe Mode appears to stop task manager from crashing and my computer from slowing down.

Here's the list of add-ons I currently have: Adobe Acrobat Ghostery uBlock Origin Webroot Filtering Extension (disabled)

Plugins: OpenH264 Video Codec provided by Cisco Widevine Content Decryption Module by google Shockwave Flash

Try disabling graphics hardware acceleration in Firefox. Since this feature was added to Firefox it has gradually improved but there are still a few glitches.

You will need to restart Firefox for this to take effect so save all work first (e.g., mail you are composing, online documents you're editing, etc.,) and then perform these steps:

In Firefox 54 and below:

1. Click the menu button and select Options (Windows) or Preferences (Mac, Linux).
2. Select the Advanced panel and the General tab.
3. Uncheck Use hardware acceleration when available.
4. Close Firefox completely and then restart Firefox to see if the problem persists.

In Firefox 55 and above:

1. Click the menu button and select Options (Windows) or Preferences (Mac, Linux).
2. Select the General panel.
3. Under Performance, uncheck Use recommended performance settings. Additional settings will be displayed.

   

4. Uncheck Use hardware acceleration when available.
5. Close Firefox completely and then restart Firefox to see if the problem persists.

Did this fix your problems? Please report back to us!

If the problem is resolved, you should check for updates for your graphics driver by following the steps mentioned in these Knowledge base articles:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

Thank you.

I have this problem as well. Unchecking hardware acceleration does not fix the problem. However, it did change what task manager showed. When hardware acceleration was enabled, Firefox was shown as having very high CPU usage (constantly > 80% on my Ivy Bridge i7). Of course, when task manager was closed it certainly didn't seem like there was any significant load since everything ran smoothly. With HW acceleration disabled, CPU usage is shown as much lower overall and Firefox only uses a few %, but the mouse stuttering and general lack of usability persists.

Glad to know I'm not alone.

So I've done everything listed here and it didn't fix it. Had our IT dept look again. They told me to just use Chrome.

Well, I believe I found the problem. I think it's the Webroot Filtering Extension, despite it being disabled. Looking at our overlapping add-ons, I ruled out uBlock Origin as the cause, uninstalled Webroot, and after a reboot everything seems to be working fine! It does happen that Firefox just updated to 57.0.4 as well, so I can't rule that out, but I'm willing to bet it was Webroot. Let me know if that works for you.