cancel
Showing results for 
Search instead for 
Did you mean: 

When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

SOLVED
Highlighted
Grand Master

When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

When trying to start Firefox again I got a message saying "Close Firefox. A copy of Firefox is already open. Only one copy of Firefox can be open at a time." This question is addressed in Mozillazine but nothing I've tried from there seems to work. I started a new Profile from the Profile Manager which at least gets me up and functioning, but weirdly enough the Manager also tells me the old (Default) profile is still running, though I can't find a way to close it. I also can't find the Default profile in my profile manager. can anyone help?

This happened

Just once or twice

== i thought I'd exited Firefox and was going in again.

1 ACCEPTED SOLUTION

Accepted Solutions
Grand Master

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

I get the same problem from time to time. It is hardly a solution but I go into Task Manager (select by right clicking on a blank area of the Start Bar) and search under Processes and, invariably, there is a "hidden" version of FF operating. I select & close it through Task Manager and then am able to re-start FF.

7 REPLIES
Grand Master

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

I get the same problem from time to time. It is hardly a solution but I go into Task Manager (select by right clicking on a blank area of the Start Bar) and search under Processes and, invariably, there is a "hidden" version of FF operating. I select & close it through Task Manager and then am able to re-start FF.

New User

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

I think this reply applies to pcs. I don't know what is referred to as a task manager of process on the mac. I've tried everything--I've reinstalled, tried to changer profiles etc, restarted computer--nothing works. When I use firefox under another user, everything is fine. I got into this problem because I was trying to import a user profile to pick up bookmarks etc. Can anyone help me and my mac? Thanks, kk

Site Moderator

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

It is the same for all platforms.
You will also get that error pop-up if the default profile no longer exists, but is still listed in profiles.ini

See: http://kb.mozillazine.org/Recovering_a_missing_profile http://kb.mozillazine.org/Profile_in_use

New User

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

Topic: 'a copy of firefox is already open'

I'm using an eMac with OS 10.4 and no firefox or mozilla is showing up on the activity monitor?

New User

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

I have the same problem - it occurs several times a week. I will have closed firefox or it may have hung and it has been Force-Quit. Either way, the message that a copy is already open appears. You are correct that the process is NOT listed in the Activity Monitor (the Mac equivalent of the Windose Task Manager). The only solution for me is to restart the computer. Mozilla -PLEASE FIX THIS!!! Thanks.

New User

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

I have the same problem on my MacBook Pro.

My solution: I deleted Firefox and don't use it. I report this to websites which try to get me to use Firefox in order to do business.

And then I go on with my life... without the hassle of this oddity which caused me so much distress. Give it a try! If you are on a Mac, Safari works great.

New User

Re: When trying to start Firefox I keep getting message saying "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I've started a new Profile but Profile Manager keeps telling me the Default one is still in use.

Had this problem on my MacBook after I deleted my profile (the profile folder is named something like asd8f7as.default). The solution for me was to open profiles.ini and delete the information about the profile I had deleted. It should look something like this:

[Profile0] Name=default IsRelative=1 Path=Profiles/2xr4hi1g.default


Delete, save, problem solved.