I tried to switch out Ethan in the Humanoid Animation Recorder sample with a custom Avatar. I followed the directions in the manual to the best of my knowledge. This is the error it gives me.

NullReferenceException: Object reference not set to an instance of an object
AnimatorAvatar.Start () (at Assets/NuitrackSDK/Tutorials/Motion Capture/FinalAssets/Scripts/AnimatorAvatar.cs:18)

Make sure that the character animator is set in the AnimatorAvatar component in the animator. You should also check the model settings: Rig should be configured for Humanoid.
Also check that all bones that you want to use in the AnimatorAvatar component are configured in the humanoid

“ArgumentNullException: Value cannot be null.
Parameter name: targetTransform
GenericRecorder…ctor (UnityEngine.Transform[] recordableTransform, UnityEngine.Transform rootTransform) (at Assets/NuitrackSDK/Tutorials/Motion Capture/FinalAssets/Scripts/GenericRecorder.cs:18)
UnityAnimationRecorder.Start () (at Assets/NuitrackSDK/Tutorials/Motion Capture/FinalAssets/Scripts/UnityAnimationRecorder.cs:39)”

Still getting the message along with the one above. This avatar was working before I updated nuitrack.

Check the values passed to GenericRecorder(Transform[] recordableTransform, Transform rootTransform) for recordableTransform and rootTransform: they should be non-null.