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. '''For Windows: ''' #On the keyboard, press '''[Windows] [[Image:Windows Key]] + [R]'''. This should bring up a ''Run'' box that contains a text field. #In that text field, type '''%APPDATA%''' and press Enter. An explorer window should open. #From that explorer window, double-click on the '''Mozilla''' folder, then double-click on '''Firefox''' and then on '''Crash reports'''. Double-click on '''submitted'''. #Now, you should see a list of files that contain reports. Go to '''View''' > '''Arrange Icons by''' > '''Modified''' to get the most recent files at the top of the window. #Open the most recent 5 files with a text editor and copy the IDs. #Paste each ID with '''bp-''' into the reply window on the forums. '''For Mac:''' #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.