SplineAnimate throws an error on Awake in Unity 6

In my project, after updating the editor version (6000.0.34f1), errors began to occur in those places where I use SplineAnimate.

For the test, I created a new clean project, added an empty game object, attached the SplineAnimate and SplineContainer components, unchecked the PlayOnAwake checkbox, but the error still occurs when starting PlayMode.

Fixed it by adding a default knot. My custom script clears and adds generated knots on start, so not much difference, but it fixes this stupid exception on awake.