We're sorry to hear that your Firefox seems to be crashing when you open it. Please perform the following steps to give us a crash report ID that helps us find out more about the cause of the crash. #Open the Finder by clicking the smiley face icon in the dock. #Navigate to the following directory: ''~ / Library / Application Support / Firefox / Crash reports / submitted''. #Now, you should see a list of files that contain reports. Click the gear icon in the toolbar (or open the ''View'' menu), then select ''Arrange by'' > ''Creation date'' 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 into the reply window on the forums. Thanks in advance! You can find more information and troubleshooting steps in the [[Firefox crashes]] article.