Error on scene save "Component outside the auto-syncable..."

I have a scene with a button that reference a Node at the same tree level of himself. Inside this Node, there is a child that happen to be an auto-syncable prefab. The parent itself is not, it just contain one. When I save the scene, I get this error, that make no sense in the contexte and should not even be a problem:

In the editor, the component outside the auto-syncable prefab can only reference to that prefab’s root node itself, but not its components or children. Detailed information:
Component: “cc.Button”, Property: “clickEvents”
Node: “Canvas/Button”

But as you will see in my demo scene, the button clickEvents reference on normal Node, not a prefab Node.

If I move the button to be a child of DummyScript node, the node it reference, then the error disappear. Also take note, the error happen on save only, and everything work fine during execution.

DummyProject.zip (213.1 KB)

Same here with CocosCreator 2.0.7

Node node has component Helloworld with property something that refers to node cocos which happens to be auto-syncable prefab. node and cocos are siblings. When I’m trying to save the scene I get following error:

In the editor, the component outside the auto-syncable prefab can only reference to that prefab's root node itself, but not its components. Detailed information:
Component: "Helloworld", Property: "something"
Node: "Canvas/node"

Sample project to reproduce https://github.com/id-ilych/cc-hello-typescript