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Firefox won't open

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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. :(

All Replies (2)

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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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Hi This fix does not work in my case!

There is no such folder as cd ~/Library/Application\ Support/Firefox

And there's no copy of firefox open.