crash when trying to equip sorcery lance

I was in my items menu about to equip a sorcery lance when i clicked A on my gamepad this came up

0.0.3v

windows 10


############################################################################################
FATAL ERROR in
action number 1
of Key Press Event for E-key Key
for object obj_itemmenu:

Variable obj_itemmenu.special_flag(100182, -2147483648) not set before reading it.
at gml_Object_obj_itemmenu_KeyPress_69
############################################################################################

stack frame is
gml_Object_obj_itemmenu_KeyPress_69 (line -1)