Firefox Won't Start

When trying to launch firefox you get a message along the lines of, "Firefox is already running, but not responding. To open a new window, you must first close the existing Firefox process, or restart your system." This sometimes happens if firefox was running when an apps machine was rebooted and lock files were not properly cleaned up. Before removing lock files manually, you should always check to make sure there isn't an instance of firefox running, perhaps you left another machine logged in and running firefox.

To check that there isn't a firefox process running try the command: ps auxww | grep <username> | grep firefox

If you do find a firefox process try sending it a kill signal: kill -9 <PID>

If you are certain this is not the case go to .mozilla/firefox/*.default/ and remove the lock and .parentlock files

apps2:~> cd .mozilla/firefox/*.default
apps2:~/.mozilla/firefox/2evgcc9w.default> ls -a

apps2:~/.mozilla/firefox/2evgcc9w.default> rm lock
apps2:~/.mozilla/firefox/2evgcc9w.default> rm .parentlock