Parameter name: The Playable is null. when switched from 2018.4.0f1 to 2019.13

Hi,
I need some help with this one,
I was going by the Unity Playables examples in the manual and created a ScriptPlayable that does some animation time scrubbing. Everything worked great in 2018 but when moved to 2019 I get a null error for the playable when using the extension methods

Here is my scriptable playable code:

Code (CSharp):

1.  
2.  
3. public class PlayQueuePlayable : PlayableBehaviour
4. {
5.     private int m_CurrentClipIndex = -1;
6.     private float m_TimeToNextClip;
7.     private Playable mixer;
8.  
9.     public void Initialize(AnimationClip[] clipsToPlay, Playable owner, PlayableGraph graph)
10.     {
11.         owner.SetInputCount(1);
12.         mixer = AnimationMixerPlayable.Create(graph, clipsToPlay.Length);
13.         graph.Connect(mixer, 0, owner, 0);
14.         owner.SetInputWeight(0, 1);
15.  
16.         for (int clipIndex = 0; clipIndex < mixer.GetInputCount(); ++clipIndex)
17.         {
18.             graph.Connect(AnimationClipPlayable.Create(graph, clipsToPlay[clipIndex]), 0, mixer, clipIndex);
19.             mixer.SetInputWeight(clipIndex, 1.0f);
20.         }
21.     }
22.  
23.     public override void PrepareFrame(Playable owner, FrameData info)
24.     {
25.         if (mixer.GetInputCount() == 0)
26.             return;
27.  
28.         // Adjust the weight of the inputs
29.         for (int clipIndex = 0; clipIndex < mixer.GetInputCount(); ++clipIndex)
30.         {
31.             var clip = ((AnimationClipPlayable)mixer.GetInput(m_CurrentClipIndex));
32.             Debug.Log(clip); //<-- Playable object exists
33.             Debug.Log("clip: " + clip.GetAnimationClip()); //<-- Playable in extension is null
34.             clip.SetTime(owner.GetTime());  //<-- Playable in extension is null
35.             if (clipIndex == m_CurrentClipIndex)
36.                 mixer.SetInputWeight(clipIndex, 1.0f);
37.             else
38.                 mixer.SetInputWeight(clipIndex, 0.0f);
39.         }
40.  
41.     }
42.  
43. }

 

Never mind I found I made a mess with the index variables