Is the Mozilla crash reporter triggered? If so please use about:crashes to link us to the crash report.
Trying this in Windows Nightly I get "Video can't be played because file is corrupt."
Apparently the crash reporter did not trigger, however I am able to see the streak of reports in about:crashes. Here is a clean one: https://crash-stats.mozilla.com/report/index/938df792-e0bc-449c-a3d5-4006b2140912
Thank you! This is not an exploitable crash (it's a null-dereference), and it's specific to mac MP3 code. I'm going to mark this bug duplicate of an existing bug tracking this crash signature, and let them know that you have reliable STR.