Created attachment 24495 [details]
HockeyApp crash log
I'm seeing a lot of hard crashes on this one in HockeyApp, and occasionally caused this myself. Not idea why, I don't even have animations running on the page I encountered this - maybe there was a progress spinner. I've attached the HockeyApp crash log, maybe it'll help.
There's also a forum entry on this one with different users seeing this happening in different scenarios - see here:
I've never seen this before, this could have been introduced with one of the more recent stable releases.
I'm going to set this to needinfo until we can hopefully get a reproduction from someone. If you have been able to cause the crash yourself without the need for HockeyApp and are able to reproduce it in a manner that could help investigation, let us know. I'd also suggest testing with the 2.4.0 prerelease and see if it affects anything as well, should you get the opportunity.
No idea what the root cause might be. This is completely random, but overall the most frequent exception I'm seeing in HockeyApp. I'll post back if I learn more.
For upkeep I'm going to mark this as not reproducible due to a lack of further reports and assume it isn't an issue as of the 2.4.0 stable release. Please of course feel free to reopen if we can get some more clearly defined steps if it is still occurring as of 2.4.0.