This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Firefox crashes

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by Matt_G

Regor
Regor
more options

Firefox crashes when launched

When I launch Firefox it appears the following text in a box: "Already running copy of Firefox. You can only run one copy of Firefox ever."

But I only have one Firefox application. I've deleted Firefox and installed it agaion but it keeps crashing and telling the same thing.

Firefox crashes when launched When I launch Firefox it appears the following text in a box: "Already running copy of Firefox. You can only run one copy of Firefox ever." But I only have one Firefox application. I've deleted Firefox and installed it agaion but it keeps crashing and telling the same thing.

Modified by Regor

All Replies (1)

Matt_G
Matt_G
more options

Hey Regor,

Have you tried starting Firefox in Safe Mode? Hold down "shift" while Firefox is starting up. If the crash doesn't happen in Safe Mode, you should read Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.

Have you looked at the "Firefox is already running but is not responding" error - How to fix Knowledge Base article? This seems like it might be perfect for the issue you've described.

There is also a lot of useful stuff in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) Knowledge Base article. If you've recently upgraded, you might want to check out this article as well.

Hopefully this helps!