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Error message to close firefox appears upon app launch and indicates that a copy of firefox is already open. How do I find the open copy and close it permanently?

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  • 38 have this problem
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  • Last reply by cor-el

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When I go into my daughter's account and try to launch Firefox (she was previously using Safari) an error message pops up indicating to "Close Firefox: A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Except that I don't see an open copy of the app, unless it somehow is launched at login, a setting I don't see either. Firefox works fine on other user accounts.

When I go into my daughter's account and try to launch Firefox (she was previously using Safari) an error message pops up indicating to "Close Firefox: A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Except that I don't see an open copy of the app, unless it somehow is launched at login, a setting I don't see either. Firefox works fine on other user accounts.

Chosen solution

Is there still a default profile folder present?

  • /Users/<user>/Library/Application Support/Firefox/Profiles/<profile>/

If not then delete the file profiles.ini
That will cause Firefox to create a new default profile.

Read this answer in context 👍 7

All Replies (3)

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Chosen Solution

Is there still a default profile folder present?

  • /Users/<user>/Library/Application Support/Firefox/Profiles/<profile>/

If not then delete the file profiles.ini
That will cause Firefox to create a new default profile.

Modified by cor-el

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thanks much! that took care of it.

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You're welcome