4.13's Sub Anim Instance node causes crash with nested usage

So with 4.13 came the SubAnimInstance node for animation graphs that I was, and still am, quite excited about.

My character has quite a large number of nested, animation affecting states: Dead vs. Alive -> In combat vs. Out of combat -> Weapon based animations -> Idle vs. Walking vs. Jumping. In 4.12 my animation blueprint had state machines within state machines, which worked fine, but were sometimes difficult to browse. With 4.13 I’ve just started moving state machines into their own animation blueprints and just invoke them using a SubAnimInstance node. So now my Main AnimBP plays the Alive AnimBP, which plays the OutOfCombat AnimBP.

This all goes well until my character goes in combat, so the Alive AnimBP switches from OutOfCombat AnimBP to the InCombat AnimBP. I think the nested use is causing the issue. Has anyone else ran into this?

The code line is crashes on is AnimInstance.h, line 1241:
check(IsInGameThread());

I just tested and I’m getting the same crashes without nested SubAnimInstance nodes. :frowning: