Crash when casting spell at enemy near you

When casting spells (I used a fireball for testing) at enemies (even if they weren't enemies before firing the fireball) in a certain area around the game crashes (log attached). This is reproducible with humanoids (both enemies and citizens) and rats (and probably more non-humanlids).

I'm using openmw 0.31.0, installed through the Debian experimental repository. My OS is Debian jessie.

(RM-1663 from redmine: created on 2014-07-18 by Sven Bartscher, , closed on 2015-01-06 by scrawl ., duplicates #1978 (closed), duplicates #1977 (closed))

Attachments: attachments.tar data.tar