Steps to reproduce:

1. Create new project
2. Enable VCS support and connect to server
3. Click on Work offline
4. Confirm the pop up

In console:
InvalidOperationException: Operation is not valid due to the current state of the object
System.Collections.Stack.Pop () (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Collections/Stack.cs:329)
UnityEngine.GUILayoutUtility.EndLayoutGroup () (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/GUILayoutUtility.cs:323)
UnityEngine.GUILayout.EndScrollView (Boolean handleScrollWheel) (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/GUILayout.cs:435)
UnityEditor.EditorGUILayout.EndScrollView () (at C:/buildslave/unity/build/Editor/Mono/EditorGUI.cs:7552)
UnityEditor.InspectorWindow.OnGUI () (at C:/buildslave/unity/build/Editor/Mono/Inspector/InspectorWindow.cs:392)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)

Reproes with PlasticSCM and Perforce

Reproduced with: 5.6.3p4
Not reproducible: 5.5.4p5, 2017.1.1p2, 2017.3.0b2