full error
InvalidCastException: Cannot cast from source type to destination type.
Inventory.LightFire (UnityEngine.GameObject campfire) (at Assets/Scripts/Inventory.js:62)
Inventory.OnControllerColliderHit (UnityEngine.ControllerColliderHit col) (at Assets/Scripts/Inventory.js:53)
UnityEngine.CharacterController:Move(Vector3)
CharacterMotor:UpdateFunction() (at Assets/Standard Assets/Character Controllers/Sources/Scripts/CharacterMotor.js:229)
CharacterMotor:FixedUpdate() (at Assets/Standard Assets/Character Controllers/Sources/Scripts/CharacterMotor.js:331)

    function OnControllerColliderHit(col : ControllerColliderHit){
    if(col.gameObject.name == "campfire"){
       if(haveMatches && !fireLit){
         LightFire(col.gameObject);
       }else if(!haveMatches && !fireLit){
       textHints.SendMessage("ShowHint", "I could use this campfire to signal for help... \n if only i could light it..");
       }
    }
}

function LightFire(campfire : GameObject){
    var fireEmitters : ParticleEmitter[];
    fireEmitters = campfire.GetComponentsInChildren(ParticleEmitter);
    for(var emitter : ParticleEmitter in fireEmitters){
       emitter.emit = true;
    }
    campfire.audio.Play();
    Destroy(matchGUI);
    haveMatches = false;
    fireLit = true;
}

any ideas

decided to try to build it and it gave me this warning

Assets/Scripts/Inventory.js(62,56): BCW0028: WARNING: Implicit downcast from 'UnityEngine.Component[]' to 'UnityEngine.ParticleEmitter[]'.