After the room, a selection of creatures dawned on me, there I only had one creature to choose, I tried to reroll it and then my screen went black and the error came up

Yep it seems that way to me too

___________________________________________

############################################################################################

ERROR in

action number 1

of Other Event: User Defined 0

for object o_reward:

DoConv :1: illegal undefined/null use

at gml_Script_unlock_baby_desc

############################################################################################

gml_Script_unlock_baby_desc (line -1)

gml_Object_o_reward_Other_10

gml_Object_o_reward_Draw_0 (line -1)