FG
💻 Software

"A copy of Firefox is already open. Only one copy of Firefox can be open at a time."

Fresh7 days ago
Mar 15, 202622903 views
Confidence Score0%
0%

Problem

I cannot start Firefox on my Mac. It just says "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I have tried restarting the computer. Any fixes? You have suggested deleting the lock files in my profile, but, I don't have a profile. I was trying to fix the problem…

Unverified for your environment

Select your OS to check compatibility.

1 Fix

Canonical Fix
Unverified Fix
New Fix – Awaiting Verification

Fix for: "A copy of Firefox is already open. Only one copy of Firefox can be open at a time."

Low Risk

To remove .parentlock files you can run the following command in the Terminal: (It's not in your profile) However as said before, removing a .parentlock file won't help fix a stuck Firefox process.

Awaiting Verification

Be the first to verify this fix

Sign in to verify this fix

Environment