Try calling validateNow() before ensureIndexIsVisible
validateNow() didn't work. The List still throws the exception when ensureIndexIsVisible is called.
I was finally able get it to work by extending List and overriding updateDisplayList.
protected override function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void
// call ensureIndexIsVisible here
you can use
Doesn't work, there's no exception but it does not scroll to the desired row (it appears to not scroll at all). I'm stuck having to extend List and overriding updateDisplayList (which works perfectly).