Error 'Language feature not implemented'

Language feature not implemented: Ambiguous(Void Pause(),Void Pause(Boolean))

Hey, I get this error and I don’t know what to do. Can anyone help?

#pragma strict

var showFire : boolean = false;

function Start()
{
    particleSystem.Pause = true;
}

function Update ()
{
    if (showFire == true) {
        particleSystem.Play = true;
    } else {
        particleSystem.Pause = true;
    }
}

Play and Pause are methods, not variables or properties.

So you should use

particleSystem.Pause();

and

particleSystem.Play();