Steps:
1. Create a script
2. Create a new scene
3. Add empty GameObject
4. Drag GameObject to Project Brower to make a prefab asset
5. Select Prefab Asset
6. Drag script onto Inspector
==>
Assertion failed on expression: '!go.TestHideFlag(Object::kNotEditable)'
UnityEditorInternal.InternalEditorUtility:InspectorWindowDrag()
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Note: Script is added to prefab asset

Expected: No assertions, script is not added to prefab asset

Take a look into attached movie for details