Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:

• Click the menu button , click Help and select Restart with Add-ons Disabled.

If Firefox is not running, you can start Firefox in Safe Mode as follows:

• On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
• On Mac: Hold the option key while starting Firefox.
• On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
  (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)

When the Firefox Safe Mode window appears, select "Start in Safe Mode".

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

Let me know if this works, or you need more help.

If the above does not help;

Let’s do a full clean re-install;

Download Firefox For All languages And Systems {web link}

Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86)

Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux

If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Look for, and remove any Mozilla or Firefox program folders. Do not remove the Mozilla Thunderbird folder if there is one.

Do Not remove any profile folders.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

Benniso said

After many years of Firefox usage it has suddenly started crashing with the error as below (I've extracted the details from from Win 10). I've tried an installation from scratch i.e. no add-ons etc and still it crashes. Can you help. Many thanks, John Peart. Description A problem caused this program to stop interacting with Windows. Faulting Application Path: C:\Program Files\Mozilla Firefox\firefox.exe Problem signature Problem Event Name: AppHangB1 Application Name: firefox.exe Application Version: 60.0.2.6730 Application Timestamp: 5b16d65f Hang Signature: e98c Hang Type: 134217728 OS Version: 10.0.16299.2.0.0.256.48 Locale ID: 2057 Additional Hang Signature 1: e98c8f522b790e3dcece48f0ac06630d Additional Hang Signature 2: 201d Additional Hang Signature 3: 201d3e5904aa8a4a3c1336b8d3395747 Additional Hang Signature 4: e98c Additional Hang Signature 5: e98c8f522b790e3dcece48f0ac06630d Additional Hang Signature 6: 201d Additional Hang Signature 7: 201d3e5904aa8a4a3c1336b8d3395747 Extra information about the problem Bucket ID: 84d333b177cf6640d440ec4a8a04ed24 (1459426084155354404)

I restarted FireFox in Safe Mode and removed all my add-ons. Then re-installed each of them in turn. This seems to have done the trick. Many thanks.

That was very good work. Well done. Please flag your last post as Solved Problem so others will know.