Should I be concerned with...

ArgumentException: get_time can only be called from the main thread.

It is posted because of this script;

var projectile : Rigidbody;
var speedBall = 100;
var timer = Time.time;

function Update () 
{

	if( Input.GetButtonDown( "Fire1") )
	{
		timer=Time.time;
	}
	
	if( Input.GetButtonUp( "Fire1") )
	{
		var powerShot = (Time.time - timer) * speedBall;
		if (powerShot > 100) 
			{
			powerShot = 100;
			}
		var instantiatedProjectile : Rigidbody = Instantiate( projectile, transform.position, transform.rotation );
		instantiatedProjectile.velocity = transform.TransformDirection( Vector3( 0, 0, powerShot ) );
		projectile.tag = "monarchProjectile";
	
		print (powerShot);
	}
}

Everything seems to work as it should, even in a windows build.

Change that to:

var projectile : Rigidbody;
var speedBall = 100;
var timer : float;

function Start () 
{
	timer = Time.time;
}

function Update ()

You can’t use Time.time while initiating the timer var. Set the timer var to 0.0 as default, and make an Awake function which sets timer to Time.time.

edit; oops late post

Ok, thx guys.