Need some help with this script....

[rojkish]

void OnStart()
{
AddEntityCollideCallback("Player","MonsterDoor","CollidePlayerWithMonsterDoor");
}

At this ^ you missed both bool abDeleteOnCollide & int alStates, making it correctly would be;

"AddEntityCollideCallback("Player","MonsterDoor","CollidePlayerWithMonsterDoor", true, 1);"

You've also missed float afFadeTime on the playsoundatentity, making it correctly would be;

"PlaySoundAtEntity("MonsterDoor", "react_scare", "Player", 0.0, false);"

Other than that there is nothing wrong with the script overall and it should work. In case it doesn't I'll just redo it all for you.

Spoiler below!

void OnStart()
{
AddEntityCollideCallback("Player", "MonsterDoor", "CollidePlayerWithMonsterDoor", true, 1);
}

////////////////////////////
// Run when entering map
void OnEnter()
{

}

////////////////////////////
// Run when leaving map
void OnLeave()
{

}



void CollidePlayerWithMonsterDoor(string &in asParent, string &in asChild, int alState)
{
SetEntityActive("Scarydude", true);
FadeRadialBlurto(1.0f, 1.0f);
PlaySoundAtEntity("MonsterDoor", "react_scare", "Player", 0.0, false);
ShowEnemyPlayerPosition("Scarydude");
}