Unknown Variable (Execution Error) - gms_init(GMS) IS 1st FUNCTION EXECUTED

Hello! I am a new user to game maker and wanted to make a fun little 2 player fighting game for my friends and I. To play with my friends I decided to try to implement GMS into my game. I followed the starter tutorial and have created the 2 OBJs and the 3 Rooms. The login window appears and I have tried logging into my actual account and using the guest function, but no matter what I do the next thing that happens is an error:
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FATAL ERROR in
action number 1
of Step Event0
for object GMS:

Push :: Execution Error - Variable Get 100031.player_id(100138, -2147483648)
at gml_Script_gms_step (line 617) - room_id = gms_other_get_real(player_id, "room");
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stack frame is
gml_Script_gms_step (line 617)
called from - gml_Object_GMS_StepNormalEvent_1 (line 1) - gms_step()