App Crashes while creating a TextMesh game object in iOS device

I have a function that will create a game object with TextMesh component dynamically, the code is as the following: // this will create a TextMesh game object in the passed parent transform public static FlyingText getInstanceWithTextMesh(string text, Vector3 pos, int fontSize, Color color, float speed, float duration, Transform parentTransform) { pos.z = parentTransform.position.z; // create game object GameObject obj = new GameObject ("FlyingText"); obj.transform.parent = parentTransform; obj.transform.position = pos; obj.transform.localScale = new Vector3 (1, 1, 1); // add TextMesh component TextMesh t = obj.AddComponent (); // !!!!!!!!!! it will crash here !!!!!!!!!!!!!! t.text = text; t.alignment = TextAlignment.Center; t.font = Resources.Load ("Fonts/"+Const.DEFAULT_FONT_NAME) as Font; t.fontSize = fontSize; t.color = color; t.characterSize = 0.1f; ... } It will crash at this line every time 100%:
**TextMesh t = obj.AddComponent ();** Here is the crash log in Xcode: ![alt text][1] There is absolutely no problem when I tested in the PC emulator. It only happens in iOS device(Android seems not happen this). One more strange thing, If I insert a TextMesh game object by editor(not by script code) and test again. Then it won't crash any more. I absolutely don't know why.... ![alt text][2] Does anyone can help? BTW, I am using Unity 5.2.1f1 and tested in iPhone 6, iOS 8.3. [1]: /storage/temp/58480-gg.png [2]: /storage/temp/58478-no-crash.jpg