How do I correct this --> (firefox:2671): GLib-WARNING **: g_set_prgname() called multiple times

According to this it looks like your profile is corrupt:
http://www.linuxquestions.org/questions/linux-software-2/firefox-will-not-launch-781224/

If you close all firefoxes (check none are running with: ps -ef | grep firef) then run:

mv ~/.mozilla ~/.mozilla_old

Then rerun the browser, should be ok. You will need to copy the bookmarks file from the old profile and rebuild but the browser will at least function

This topic on ubuntuforums.org also suggests that and a few other ideas to get past this warning.

http://www.uluga.ubuntuforums.org/showthread.php?t=1349192

Good luck

re: actionparsnips' proposed solution- I have attempted a new user profile that did not work. If you look @ the bug reports I have filed it also comes in xsession errors. Regarding rebuilding mozilla that may be logical but I do not think so. system updates and upgrades should rebuild. Plus I would lose all of my bookings and trails and logins. The browser functions I just get the warning that I am supposed to iggy( I guess) everytime it starts.

re: Jeruvys' proposed solution- The forum post that you speak of has no definitive answer. In fact in offers several solutions that seem illogical. And the case scenario in general is different. My firefox will start- it just has the warning after every load.

There are several sql files unique to my profile would be one main reason not wanting to recreate mozilla file. I read that the compatibility file should be renamed also but that file just shows the xulrunner ver and ff ver

Sorry please try again...

Sure.

It's a warning. It should not cause any problems unless you have more information about your specific issue to provide.
I never stated this was a definitive solution, even proposed, just that here were some ideas others have tried.
Did you actually try any?

Since your Firefox works regardless of the warning, you may want to track this with the existing bug reports and followup as needed, or simply wait if someone has a better idea of the problem.

Sorry my idea's didn't help.

I've got the same warning all along in .xsession-errors, but it didn't bother me since FF works so far and a warning isn't an error.
The only issue I've experienced is after updating any extension and FF needs a restart, it wont terminate. Noticed it because conky is still showing firefox process and CPU is up. I just give it a killall in this case.
In all other cases it terminates properly.
Thus I give +1 to comment #12, it's a terminate issue not a restart issue.
http://www.linuxquestions.org/questions/linux-software-2/firefox-will-not-launch-781224/?s=0b87ec9af4b9062fbab1631d04abac40#post3822096

Try adding the mozilla ppa and upgrading. It will give a later build of the browser

sudo add-apt-repository ppa:ubuntu-mozilla-daily/ppa; sudo apt-get update; sudo apt-get upgrade

Then rerun, if you renamed yuor profile you should rename back to retain settings as you have isolated the issue away from a bad profile