Null Reference Exception : The Playable Graph is null

In the Class Movie , I am pausing a timeline when its gameobject is disabled

Code (CSharp):

1. public void PauseMovie()
2.     {
3.         myPlayableDirector.playableGraph.GetRootPlayable(0).SetSpeed(0);
4.     }

and then Resuming it when its gameobject is enabled

Code (CSharp):

1. public void ResumeMovie()
2.     {
3.        myPlayableDirector.playableGraph.GetRootPlayable(0).SetSpeed(1);
4.     }

Play on awake is false.

when I get this error :
NullReferenceException: The PlayableGraph is null.

UnityEngine.Playables.PlayableGraph.GetRootPlayableInternal (System.Int32 index) <0x3f964f10 + 0x00072> in <d616be05755d41a089810b5c14e4dd50>:0

UnityEngine.Playables.PlayableGraph.GetRootPlayable (System.Int32 index) (at C:/buildslave/unity/build/Runtime/Export/Director/PlayableGraph.bindings.cs:29)

Movie.ResumeMovie () (at Assets/Final/Scripts/Movie.cs:86)


What am I doing wrong?

 

This works :
GameObject to which Playable Director is attached is enabled
PlayableDirector.Play() is called
PlayableDirector is Paused using GetRootPlayable(0).SetSpeed(0)
PlayableDirector is Resumed using GetRootPlayable(0).SetSpeed(1)

This Does Not Work:
GameObject to which Playable Director is attached
PlayableDirector.Play() is called
PlayableDirector is Paused using GetRootPlayable(0).SetSpeed(0)
GameObject to which Playable Director is attached is disabled
GameObject to which Playable Director is attached is enabled
PlayableDirector is Resumed using GetRootPlayable(0).SetSpeed(1) => This gives error

 

Can we get the Null Ref error changed, as the graph is a struct? That error does not make it clear we should be using IsValid() in place of a null check

 

Is there a way around this limitation? I don't want the playableGraph to get deleted. I intent to re-enable it later and would like it to resume.
It seems like the AnimationClips are getting destroyed from the graph when I disable the gameobject. I want to keep these.

 

Is this something I should be worrying about down the road? Nothing seems to be breaking but when my timeline is finished it's just returning null which makes sense.

 

I have only one animation in project - in one compilation file. Translator gives me this error:
"NullReferenceException: The PlayableGraph is null." without indicating what is the line of the error.
I use this code from documentation:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.Playables;
5. using UnityEngine.Animations;
6.  
7. [RequireComponent(typeof(Animator))]
8. public class Test : MonoBehaviour
9. {
10.     [SerializeField] public AnimationClip clip;
11.     [SerializeField] PlayableGraph playableGraph;
12.  
13.     // Start is called before the first frame update
14.     void Start()
15.     {    
16.         StartCoroutine(MyAnimation());
17.     }
18.  
19.     private IEnumerator MyAnimation() {
20.  
21.         playableGraph = PlayableGraph.Create();
22.  
23.         playableGraph.SetTimeUpdateMode(DirectorUpdateMode.GameTime);
24.  
25.         var playableOutput = AnimationPlayableOutput.Create(playableGraph, "Animation", GetComponent<Animator>());
26.  
27.         // Wrap the clip in a playable
28.  
29.         var clipPlayable = AnimationClipPlayable.Create(playableGraph, clip);
30.  
31.         // Connect the Playable to an output
32.  
33.         playableOutput.SetSourcePlayable(clipPlayable);
34.  
35.         // Plays the Graph.
36.  
37.         playableGraph.Play();
38.         yield return new WaitForSeconds(1.5f);
39.  
40.         Destroy(this.gameObject);
41.     }
42.  
43.     void OnDisable()
44.     {
45.  
46.         // Destroys all Playables and PlayableOutputs created by the graph.
47.  
48.         playableGraph.Destroy();
49.     }
50. }

How can I fix it? IsValid doesn't help. (What should I do in other cases when I have for example memory leak - (index out of array bounds) and I don't know the exact line?). How the PlayOnAwake flag is related to animation? -This flag is on the audio source. I could play the sound with PlayOneShot() but it is not an animation. V2019.4.15.f1