(SOLVED)Help? Getting an error without a reason?

Hello everuyone, i got an error at making my new game, this is the error: ERROR!!! :: ############################################################################################
FATAL ERROR in
action number 1
of Step Event0
for object oGMS:


Variable oOtherPlayer.player_id(100101, -2147483648) not set before reading it.
at gml_Script_gms_step (line 677) - room_id = gms_other_get_real(player_id, "room"); ############################################################################################
--------------------------------------------------------------------------------------------
stack frame is
gml_Script_gms_step (line 677)
called from - gml_Object_oGMS_StepNormalEvent_1 (line 1) - gms_step();

Idk what's causing this bug, Can someone help me?

PD: I DON'T HAVE ANY VARIABLE NAMED player_id.
Plz help!!
Discord: TheProhAslon#1656