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.

1. (OS X 10.6 or previous) Click the Finder icon in the dock. Your home folder will be selected. In the right side of the window, click the Library folder to open it. Then open the "Application Support" folder, the "Firefox" folder, the "Crash Reports" folder and finally the "submitted" folder.
   (OS X 10.7 or above) 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. Then open the "Application Support" folder, the "Firefox" folder, the "Crash Reports" folder and finally the "submitted" folder.
2. Open the 5 most recent files with a text editor and copy the IDs.
3. 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.

This is the only file in that folder:

bp-806d5b67-ca33-4a0a-a41a-ddd1a2151214.txt

Thanks.

Product Firefox Release Channel release Version 42.0 Build ID 20151029151421 OS OS X 10.10 OS Version 10.10.5 14F1505

Is there a reason for using an old version?

bp-806d5b67-ca33-4a0a-a41a-ddd1a2151214

Signature: nsCOMPtr_base::assign_from_qi | nsConsoleService::ClearMessagesForWindowID

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

I'm using that OS version so I can run Pro Tools 11.