Getting this error when, in editor mode, i enter or exit a scene that contains an imported VRoid model.
( ERROR: scene/3d/node_3d.cpp:466 - Condition "!is_inside_tree()" is true. Returning: Transform3D()
)
Had similar issues on owned code, and it always was for accessing Transforms prior to full initialization / parenting it.
(Sorry for the c# example, but it's what i'm used to)
For example:
var player = new AudioStreamPlayer3D{...};
var tree = ... ;
var targetParent = ... ;
targetParent.AddChild(player);
player.GlobalPosition = globalPosition; <----- This, if it was written before the previous call to AddChild(), the error would trigger.
...