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Firefox won't open

Posted

After updating my mac, Firefox stopped working so I deleted it and reinstalled. But now when I try to open it, it says "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Even if I force stop Firefox then try to reopen, then deleted it again and reinstalled, I keep getting this error. :(

After updating my mac, Firefox stopped working so I deleted it and reinstalled. But now when I try to open it, it says "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Even if I force stop Firefox then try to reopen, then deleted it again and reinstalled, I keep getting this error. :(
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Additional System Details

Application

  • User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.122 Safari/537.36

More Information

Eve
  • Top 25 Contributor
  • Administrator
72 solutions 436 answers

Try opening the Terminal app and pasting this in

cd ~/Library/Application\ Support/Firefox/Profiles/*.default

and finding the lockfile and deleting it by entering this command

rm -rf .parentlock

and then try launching firefox.

Try opening the Terminal app and pasting this in '''cd ~/Library/Application\ Support/Firefox/Profiles/*.default''' and finding the lockfile and deleting it by entering this command '''rm -rf .parentlock''' and then try launching firefox.
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