I am using 2D Toolkit 2.5.6 with Unity 2017.1.1f1. I am completely new to tk2d, and no great shakes with Unity either, so I may well have done something stupid.
I have imported a sprite sheet image into a tk2d Sprite Collection, and I can see that it has isolated the individual sprites correctly into their own images.
I have created a Sprite Animation that refers to this collection. I asked tk2d to fill the clip with the "Autofill 1.9" button, which it did correctly. I can click the "Play" button and see my sprite animating as I expect in the Sprite Animation editor.
So now I add a sprite with GameObject -> Create Other -> tk2d -> Sprite with Animator. That lets me select my Sprite Collection, and it then auto-selects the first image as "Sprite", and that image is displayed underneath, exactly as expected. However, when I try to change the "Anim Lib" in the "Tk 2d Sprite Animator" section, I see my SpriteAnimation in the drop down box, but when I try to select it, it just silently reverts to the default (first) one. At the same time, I get this error logged in the console:
NullReferenceException: Object reference not set to an instance of an object
tk2dSpriteAnimatorEditor.OnInspectorGUI() (at Assets/TK2DROOT/tk2d/Editor/Sprites/tk2dSpriteAnimatorEditor.cs:91)
The line of code in question is this:
if (animator.Library.clips.Length > 0)
Can you help me to understand what the problem is, or how I can find out more about what's going on?