Info window doesn't appear attaching MonoBehaviour script to any game object from "Editor" folder.

Expected to see info window with information "To attach script it has to be outside 'Editor' folder".

Only error message appears in the console:

Instance of ExampleCS couldn't be created. The the script class needs to derive from ScriptableObject.
UnityEditorInternal.InternalEditorUtility:HierarchyWindowDrag(HierarchyProperty, Boolean, Int32)
UnityEditor.DockArea:OnGUI()

Repro steps:
1. Create new project;
2. Create folder "Editor";
3. In this folder create any script and try to attach to main camera or game object;
4. No info window appears, only error in the console;

Reproducible on 4.5.0a5;