Steps to Repro:
1. Open an attached project or create a new project and open a sample scene
2. Open the Lighting Settings window by going to Window > Rendering > Lighting Settings
3. In the Project View, create a new scene by right-click > Create > Scene
4. Drag and drop the newly created scene into the Hierarchy view
5. Right-click on that scene in the Hierarchy view and select Set Active Scene
6. Right-click on that same scene in the Hierarchy view and select Remove Scene while the Lighting Window is open/docked
7. Observe the error in the console

Actual Result:
Observe error in the console

Note:
Make sure lighting window is currently active

Occurring with:
2018.3.0a2, 2018.2.0b9, 2018.2.0b1, 2018.1.2f1, 2018.1.0b13, 2018.1.0b6

Working with:
2018.1.0b5, 2018.1.0b1, 2017.4.3f1

Environment:
Windows and Mac

Stack Trace:
SerializedObject target has been destroyed.
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)