iTween call producing NullReferenceException

Questions & Answers
1

Hey, guys.

When I run this short script, I’m getting a NullReferenceException error. I have no idea why. The error points to this line in iTween:

if(tweenArguments.Contains("looktarget") && isRunning){

I know it’s the “MoveBy” call, because the other part is working correctly–but no luck with the first bit.

Here’s the script. Any ideas about what I’m doing wrong?

UPDATE: Tried using even a basic MoveBy iTween, and no luck. Is there something wrong with the way I’m calling it from the Start function?

private var moveTime;
private var moveDistance;
private var fadeTime;

function Start()
{
		moveTime = Random.Range(3,4);
		moveDistance = Random.Range(.1,.3);
		fadeTime = Random.Range(1,4);
		moveDown();
		fadeOut();
}

function moveDown()
{
	
	iTween.MoveBy(gameObject, {"amount" : Vector3(0,-1*moveDistance,0), "time": moveTime, "easetype" : "easeInOutQuad", "oncomplete" : "moveUp", "oncompletetarget" : gameObject});
}

function moveUp()
{
	iTween.MoveBy(gameObject, {"amount" : Vector3(0,moveDistance,0), "time": moveTime, "easetype" : "easeInOutQuad", "oncomplete" : "moveDown", "oncompletetarget" : gameObject});
}

function fadeOut()
{
	iTween.FadeTo(gameObject, {"alpha" : 0, "time": fadeTime, "easetype" : "easeInOutQuad", "oncomplete" : "fadeIn"});
}

function fadeIn()
{
	iTween.FadeTo(gameObject, {"alpha" : 1, "time": fadeTime, "easetype" : "easeInOutQuad", "oncomplete" : "fadeOut"});
}
3

I’d like to confirm that this happened to me too. This must be some sort of iTween bug.

Not sure how-- but four separate iTween scripts mysteriously appeared on my game object. I didn’t put them there! In fact, they were set to a quadratic ease (default?) which I hadn’t used… so no idea how they appeared.

I notice that when I hit play, iTween does instantiate some sort of iTween script on my gameobject. However it usually disappears when you hit stop. Several accrued on my go however. Perhaps if I crashed or something the instantiated script stuck to my prefab and then didn’t destroy? Very weird and annoying bug!

4

SOLVED–

Okay user error: turns out I had TWO iTween folders (ie duplicates) in my project. I guess when I updated once it didn’t overwrite the old one, and gave me a new different version instead. So I had two iTween versions coexisting.

Ugh. That took me four hours of my life to figure out.

But once I deleted the old iTween folder it now works fine. Hope someone finds that helpful!

2

I had an unexpected Null Reference Exception from iTween happen to me when the iTween script was mysteriously set on a GameObject in the inspector. Perhaps that happened to you too.