OS X 10.8.5 with Firefox 45.0.2. Buying a new MAC is not an option; hence, the version of Firefox. Crashes started weeks ago, usually at startup. On the rare occasion, it would work for a few minutes and then crash. Same in safe mode. As far as I can tell, drivers are updated. I turned off acceleration. No difference. I used the Refresh Firefox feature. No difference. I did a clean install of Firefox. It worked for a day. It continues to crash on startup, or works for a while (a few minutes to an hour or two) and then crashes. ID: 77fcead0-87ca-43da-a0b4-0c0542160927 Also noticed this: Signature: unsigned long js::gc::Arena::finalize<T> Not sure what this means or how to fix it. Sorry about the comment (in the crash report). Just very frustrated. I'm using safari to submit this. I've used firefox for years. I don't want to switch unless I absolutely have no choice. I'm hoping you will be able to fix this.