Como Corrigir esse código ?

Apresentava o seguinte erro:

___________________________________________
############################################################################################
ERROR in
action number 1
of Step Event0
for object obj_inimigo_1:

script_execute argument 1 incorrect type (undefined) expecting a Number (YYGI32)
at gml_Object_obj_inimigo_1_Step_0 (line 2) - script_execute(estado);
############################################################################################
gml_Object_obj_inimigo_1_Step_0 (line 2)

Após uma pequena modificação no "step" do inimigo:
De:
/// @description Insert description here
randomize();

estado = scr_slime_escolher_estado; <<<<<<<<
prox_estado = 0;
Para:
/// @description Insert description here
randomize();

estado = scr_slime_escolher_estado(); <<<<<<<
prox_estado = 0;

Tambem tentei executar o script diretamente ao invés de armazena-lo em uma variável. Mas continua apresentando o seguinte erro:

___________________________________________
############################################################################################
ERROR in
action number 1
of Create Event
for object obj_inimigo_1:

Variable obj_inimigo_1.dist_aggro(100006, -2147483648) not set before reading it.
at gml_Script_scr_slime_checar_personagem (line 28) - if distance_to_object(obj_Zaniph) <= dist_aggro{
############################################################################################
gml_Script_scr_slime_checar_personagem (line 28)
gml_Script_scr_slime_escolher_estado (line 34) -
scr_slime_checar_personagem();
gml_Object_obj_inimigo_1_Create_0 (line 4) - estado =
scr_slime_escolher_estado();



Obs: obj_Zaniph é o personagem.









Objeto Inimigo:

-Create:
/// @description Insert description here
randomize();

estado = scr_slime_escolher_estado;
prox_estado = 0;

hveloc = 0;
vveloc = 0;
veloc = 0.2;
veloc_perseg = 0.5;

dest_x = 0;
dest_y = 0;

alarm[0] = -1;

dist_aggro = 50;
dist_desaggro = 100;

-Step:
/// @description Insert description here
script_execute(estado);

depth = -y;

-Draw:
/// @description Insert description here
draw_sprite(spr_slime_sombra, 0, x, y + 1);
draw_self();

if dest_x < x{
image_xscale = -1;
}
else{
image_xscale = 1;
}

-Alarm 0:
/// @description Insert description here
estado = scr_slime_escolher_estado();
alarm[0] = irandom_range(120, 300);







Script Inimigo:
// Script assets have changed for v2.3.0 see
function scr_slime_colisao(){

if place_meeting(x + hveloc, y, obj_parede){
while !place_meeting(x + sign(hveloc), y, obj_parede){
x += sign(hveloc);
}

hveloc = 0;
scr_slime_escolher_estado();
}

x += hveloc;

if place_meeting(x, y + vveloc, obj_parede){
while !place_meeting(x, y + sign(vveloc), obj_parede){
y += sign(vveloc);
}

vveloc = 0;
scr_slime_escolher_estado();
}

y += vveloc;
}

function scr_slime_checar_personagem(){
if distance_to_object(obj_Zaniph) <= dist_aggro{
estado = scr_slime_perseguindo;
}
}

function scr_slime_escolher_estado(){
scr_slime_checar_personagem();

prox_estado = choose(scr_slime_andando, scr_slime_parado);

if prox_estado == scr_slime_andando{
estado = scr_slime_andando;
dest_x = irandom_range(0, room_width);
dest_y = irandom_range(0, room_height);
}
else if prox_estado == scr_slime_parado{

}
}

function scr_slime_andando(){
scr_slime_checar_personagem();

image_speed = 1;

if distance_to_point(dest_x, dest_y) > veloc{
var _dir = point_direction(x, y, dest_x, dest_y);
hveloc = lengthdir_x(veloc, _dir);
vveloc = lengthdir_y(veloc, _dir);

scr_slime_colisao();
}
else{
x = dest_x;
y = dest_y;
}
}

function scr_slime_parado(){
scr_slime_checar_personagem();

image_speed = 0.3;
}

function scr_slime_perseguindo(){
image_speed = 1.5;

dest_x = obj_Zaniph.x;
dest_y = obj_Zaniph.y;

var _dir = point_direction(x, y, dest_x, dest_y);
hveloc = lengthdir_x(veloc_perseg, _dir);
vveloc = lengthdir_y(veloc_perseg, _dir);

scr_slime_colisao();

if distance_to_object(obj_Zaniph) >= dist_desaggro{
estado = scr_slime_escolher_estado;
alarm[0] = irandom_range(120, 300);
}
}