When you start Firefox again, does Firefox behave as though nothing unusual happened, or like it crashed?

If Firefox isn't detecting a crash, try keeping an extra window or two open and see whether you notice a pattern of a particular website closing itself. Another user reporting something like that happening with Earthlink email, but we never got to the bottom of it.

If Firefox is detecting a crash, could you try running in Firefox's Safe Mode for a while? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Use Troubleshoot Mode in Firefox.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

If you have submitted crash reports then please post the IDs of one or more recent crash reports that start with "bp-":

• bp-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

You can find the report ID of recent crash reports on the "Help > Troubleshooting Information" page (about:support).

• click the "All Crash Reports" button on this page to open the about:crashes page and see all crash reports.

Alternatively you can open about:crashes via the location/address bar.

See also:

• http://kb.mozillazine.org/Mozilla_Crash_Reporter
• https://support.mozilla.org/kb/Mozilla+Crash+Reporter

If you can't open Firefox, see:

• http://kb.mozillazine.org/Mozilla_Crash_Reporter#Location_of_crash_reports
• http://kb.mozillazine.org/Mozilla_Crash_Reporter#Viewing_crash_reports

• https://developer.mozilla.org/How_to_get_a_stacktrace_for_a_bug_report