Steps to reproduce :

- create a new project
- create a cube
- add the Image or Text component to it and notice the error

Transform has SetIsDispatchInterested present when destroying the hierarchy. Systems must deregister themselves in Deactivate.
UnityEditor.HostView:OnGUI()

Pressing Undo will generate another error :

System is not interested in this transform, SetSystemInterested may only be called on transforms that are set interested.

*Note :
Regression from 5.5.