Fixfor is already running

Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

http://www.mattcutts.com/blog/how-to-fix-firefox-is-already-running-error/

1) 通过 “ps auxwww | grep firefox” 找到firefox进程号, 然后“kill [processnumber]”.

2) 如果以上还不能解决, Step 1. 找到firefox的profile文件, 通常是 ~/.mozilla/firefox/profiles.ini 该文件里面会说明Path, 比如Path=src6ip5x.default Step 2. 在Path的路径下, 删除lock files. 需要删除“lock”和“.parentlock” .