Browser issue Facebook video browser crash bug


Active member
I just found a bug within facebook videos that affects XenForo. I've tried it here on for now!)/my own sites and it instantly crashes Firefox, Chrome/etc seem unaffected.

I'm on the latest Firefox version and it seems others have had this issue.

How to replicate: Simply post a facebook video url. Once embedded the page will crash the browser if viewed with Firefox.

I tested this with all Firefox plugins disabled and in safe mode so don't think it's a plugin. It could be Firefox itself though?

EDIT: Made a post with a video here: Don't click if you've got important stuff open! :confused:

EDIT2: Doesn't seem to affect Firefox mobile. Going to boot up another pc and try it on that.
EDIT3: Doesn't happen on Windows 10 only Windows 7 so far. Going to get another going as this is weird.
EDIT4: Now I'm clueless. I've tried 3 different computers but it seems to be random and only happening to one of the 3. My users have said they're having issues too so there has to be an issue somewhere.

Has anybody else had this issue?
Last edited:


XenForo developer
Staff member
I don't have a system where it will crash, but if this is truly browser and OS specific, that would appear to point to a Firefox bug. This would likely be something to report in the FF bug tracker.

In terms of XF, we're not actually causing the embed to display; that's actually done by the Facebook JS. The only thing we trigger is loading the FB JS and telling it to parse the page for embeds. As such, we don't really have much influence. (Plus if I can't reproduce it, I can't even do testing to see where it happens.)