See Troubleshoot Firefox crashes (closing or quitting unexpectedly) or Firefox hangs or is not responding - How to fix

Can you reinstall and try again, if you havent already.

The folders deleted, will not delete your profile (bookmarks, passwords etc.).

Note: You might want to print these steps or view them in another browser.

1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
3. Delete the Firefox installation folder, which is located in one of these locations, by default:
   • Windows:
     • C:\Program Files\Mozilla Firefox
     • C:\Program Files (x86)\Mozilla Firefox
   • Mac: Delete Firefox from the Applications folder.
   • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
4. Now, go ahead and reinstall Firefox:
   1. Double-click the downloaded installation file and go through the steps of the installation wizard.
   2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

If you are having trouble installing install the full version instead.

• https://www.mozilla.org/en-US/firefox/all/

Thanks Nellus91. That page is what brought me here after I'd tried everything else. All of my software is up to date; I reset, uninstalled, reinstalled, deleted all preferences and profiles, started up in safe mode, tested my ram, looked at the latest issues page, have no hardware issues that I know of, and have no anti-virus software. I read the answers to other people's crash-on-startup questions, and none applied here. The only thing in my crash reports folder is a file called InstallTime20130910160258 which has in it only this: 1381160278.

Thanks, Waka. I deleted Firefox from the Applications folder. I deleted org.mozilla.firefox.plist from my Preferences folder. I deleted the whole Firefox folder from Application Support. Then I reinstalled a fresh new version of Firefox. No Firefox windows open, since it crashes at startup, but I ensured the application wasn't open when doing all this.

Does the profile manager crash too, can you make a new profile.

• Profile Manager - Create, remove or switch Firefox profiles

Stop force quitting on old firefox version Try installing newer ones

I'm able to open the profile manager through the terminal, and I deleted the default profile, and made a new profile, but Firefox still crashes after I click "Start Firefox". Sometimes it won't even say Firefox in the menus when I click it or command-tab to get to it, but it is lit in the dock and appears in the Force Quit Applications window. Occasionally, if I wait several minutes, it opens a window at the top which it says "The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can cause this problem." (I have no security software) But I still have spinning rainbow ball and it's still unresponsive.

SEE: Fix "The bookmarks and history system will not be functional" error message article.

Thanks, Waka, but I trash the places.sql file and it's recreated every time I uninstall, so I don't think that's the problem. It only gives me that message about 25% of the time (the other 75% I get no window or menus at all), and hangs unresponsive regardless.

Try to do a check for corrupted and duplicate fonts and other font issues:

• http://www.thexlab.com/faqs/multipleappsquit.html - Font Book 2.0 Help: Checking for damaged fonts
• http://www.creativetechs.com/iq/garbled_fonts_troubleshooting_guide.html

Thanks cor-el. I used Font Book and FontNuke. Repaired a few minor problems, but it didn't solve the Firefox problem. Repaired permissions while I was at it, but to no avail. (I don't need to reinstall again after fixing fonts, do I?)