IronBackpacks-1.8.9-2.0.0.jar caused a crash when I was killed by a Fallen Knight (EnderZoo-1.8.9-1.1.2.jar) on a ladder.
I did not have a backpack in my inventory.

Here's the crash report:
http://pastebin.com/Hzz3vt30

Dupe of #47 (different cause, same issue)