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Firefox will not start - crasing on startup

  • 3 replies
  • 2 have this problem
  • 2 views
  • Last reply by cor-el

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When I try to start firefox, I get a message saying firefox crashed on startup, then asking to submit a report. I have tried to submit a report but that crashes too.

Firefox did work under my daughter's profile in Windows 7.

Upon retiring last night around midnight I put the computer to sleep, this morning it was off. The last thing I did was watch a show on amazon prime.

Thank You.

When I try to start firefox, I get a message saying firefox crashed on startup, then asking to submit a report. I have tried to submit a report but that crashes too. Firefox did work under my daughter's profile in Windows 7. Upon retiring last night around midnight I put the computer to sleep, this morning it was off. The last thing I did was watch a show on amazon prime. Thank You.

All Replies (3)

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Sorry you are havving problems.
We need the CrashID, please see

Please read the above linked article and find a couple of recent submitted Crash IDs by going to about:crashes using the location bar. Paste them into your next reply.

Note many startup crashes at present are caused by malware see

You already have a toolbar or something corrupting your User Agent String, that probably also needs attention, but we need to sort out the crash first.

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P.S. I guess I should have also mentioned

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If you can't open Firefox then see:


Try to 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.

You can use one of these to start Firefox in Safe mode:

  • On Windows, hold down the Shift key while starting Firefox with a double-click on the Firefox desktop shortcut
  • On Mac, hold down the Options key while starting Firefox
  • Help > Restart with Add-ons Disabled