Thanks to all the players who submitted bug reports I finally found the cause of two relatively frequent crash bugs. I have not been able to reproduce the bugs myself, but the debug info that I had at hand makes me confident that they are solved. Still, if you happen to come across a crash bug please send the bug report to me!
Some minor changes along with the bug fixes:
#386 Fix crash bugs
#387 Allies should not be able to swap places with NPCs
#389 Some creatures should never start as passive
#390 Update graphics for Training dummy and Prismatic band