AnimationTree - Object was deleted while awaiting a callback

[ghost]

The error "Object was deleted while awaiting a callback" appears when I try to edit a blend tree graph node inside an AnimationTree:

I use Godot 3.2.2

I have an AnimationTree node in my scene. The root of the AnimationTree node is an AnimationNodeBlendTree. In the graph editor, there are OneShot nodes, Transition nodes, Blend2 and Blend3 nodes, a StateMachine, TimeScales - and two BlendTree nodes.

Each of those two BlendTree nodes inside the AnimationTree (which has an AnimationNodeBlendTree root) freezes the engine when I want to edit them. Only once in a while I am able to open those two BlendTree nodes when I press the edit button, but the rest of the time the engine hangs.

[Calinou]

Duplicate of #35653 (the underlying issue is the same).