Crash after defeating pack of creatures with Horde prefix

(Version 0.5.4)

Crash happened right after killing the last one on screen, before any end of battle text came up.


############################################################################################
FATAL ERROR in
action number 1
of Step Event0
for object obj_battlecontroller:

Push :: Execution Error - Variable Index [0,1] out of range [1,1] - -1.crits(100271,1)
at gml_Script_bc_CreatureStartOfTurn
############################################################################################

stack frame is
gml_Script_bc_CreatureStartOfTurn (line -1)
gml_Object_obj_battlecontroller_Step_0