We're sorry to hear that Firefox is crashing when you open it. Please do the following to give us crash IDs that will help us understand more about the crash. #Click the '''Finder''' icon in the dock. On the menu bar, click the '''Go''' menu, hold down the '''option''' or '''alt''' key and select ''Library''. A window will open containing your Library folder. #Open the "Application Support" folder, the "Firefox" folder, the "Crash Reports" folder and finally the "submitted" folder. #Open the 5 most recent files with a text editor and copy the IDs. #Paste each ID with '''bp-''' into the reply window on the forums. Thanks in advance! You can find more information and troubleshooting steps in the [[Troubleshoot Firefox crashes (closing or quitting unexpectedly)]] article.