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.

1. Open the Finder by clicking the smiley face icon in the dock.
2. Navigate to the following directory: ~ / Library / Application Support / Firefox / Crash reports / submitted.
3. 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.
4. Open the most recent 5 files with a text editor and copy the IDs.
5. Paste each ID 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.

Start Firefox in Safe Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

If it does work in Firefox Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.

• Use "Disable all add-ons" on the Safe Mode start window to disable all extensions.
• Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

See also:

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes