Game not working anymore suddenly ("battlecontroller")

So I haven’t encountered any error in the whole ~ 60 hours I played this game (which I find quite good by the way :slight_smile: ).

When I just wanted to log in on steam again, I get the same error every time I start a battle. It affects even different saves. Reinstalling as well as verifying integrity of game cache is not working at all. I’m finding myself really confused … is there anything I can do? Everything worked like a charm before :(.

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

Variable obj_event.damage(100268, -2147483648) not set before reading it.
at gml_Script_bc_ExecuteEvents
############################################################################################

stack frame is
gml_Script_bc_ExecuteEvents (line 0)
gml_Object_obj_battlecontroller_Step_0

Edit: Windows 7, just since today with the newest patch (1.1.1?)