Steps to reproduce:
1. Open attached project.
2. Open scene named "Test".
3. In the "Hierarchy" window create a new game object.
4. Add component (script) named "ViewStateController".
5. In the "inspector" window click on "Initialize" button.
6. Click on "Create Manager" button.
7. Add some states by clicking "New Sate" button in the rollout.
8. Rename Manager by altering text field at the top of rollout and click on "Rename" button.
9. Delete any state by pressing red X button that is located to the right of the state.

Actual result:
The Editor crashes and "Unity Bug Reporter" window appears.

Expected result:
The Editor should not crash.

Reproduced with:
5.3.5f1, 5.3.6f1, 5.3.5p8, 5.4.0f1.

Cannot reproduce with:
5.1.5f1, 5.2.5f1, 5.5.0a3 (due to Scripting API Update).

========== OUTPUTING STACK TRACE ==================

0x0000000140B30026 (Unity) GetAffectedUnitySceneHandles
0x0000000140B89FAE (Unity) RegisterUndo
0x00000001413987E2 (Unity) Undo_CUSTOM_RegisterCompleteObjectUndoMultiple
0x0000000027603AA9 (Mono JIT Code) (wrapper managed-to-native) UnityEditor.Undo:RegisterCompleteObjectUndoMultiple (UnityEngine.Object,UnityEngine.Object[],string,int)
0x000000002760398A (Mono JIT Code) [C:\buildslave\unity\build\artifacts\generated\common\editor\UndoBindings.gen.cs:46] UnityEditor.Undo:RegisterCompleteObjectUndo (UnityEngine.Object,string)
0x0000000027602A5A (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\StateMachine.cs:48] UnityEditor.Animations.PushUndoIfNeeded/PushUndoIfNeededImpl:DoUndo (UnityEngine.Object,string)
0x0000000027602988 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\StateMachine.cs:22] UnityEditor.Animations.PushUndoIfNeeded:DoUndo (UnityEngine.Object,string)
0x0000000027622DAB (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\StateMachine.cs:374] UnityEditor.Animations.AnimatorStateMachine:RemoveState (UnityEditor.Animations.AnimatorState)
0x0000000027620ACC (Mono JIT Code) [C:\Users\Admin\Downloads\case_810867-ViewStateManager\Assets\VSM\Editor\VSMInspector.cs:446] Revenga.VSM.ViewStateControllerInspector:DeleteAnimatorState (Revenga.VSM.VSMManager,Revenga.VSM.VSMState)
0x000000002761FCFD (Mono JIT Code) [C:\Users\Admin\Downloads\case_810867-ViewStateManager\Assets\VSM\Editor\VSMInspector.cs:604] Revenga.VSM.ViewStateControllerInspector:DeleteState (Revenga.VSM.VSMManager,Revenga.VSM.VSMState)
0x0000000027617AFC (Mono JIT Code) [C:\Users\Admin\Downloads\case_810867-ViewStateManager\Assets\VSM\Editor\VSMInspector.cs:181] Revenga.VSM.ViewStateControllerInspector:DrawStates (Revenga.VSM.VSMManager,Revenga.VSM.VSMManager)
0x0000000027607092 (Mono JIT Code) [C:\Users\Admin\Downloads\case_810867-ViewStateManager\Assets\VSM\Editor\VSMInspector.cs:162] Revenga.VSM.ViewStateControllerInspector:DrawViewStateManagers ()
0x00000000275EC7A7 (Mono JIT Code) [C:\Users\Admin\Downloads\case_810867-ViewStateManager\Assets\VSM\Editor\VSMInspector.cs:92] Revenga.VSM.ViewStateControllerInspector:OnInspectorGUI ()
0x0000000027585B72 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Inspector\InspectorWindow.cs:1231] UnityEditor.InspectorWindow:DrawEditor (UnityEditor.Editor,int,bool,bool&,UnityEngine.Rect&)
0x0000000024DF9858 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Inspector\InspectorWindow.cs:1028] UnityEditor.InspectorWindow:DrawEditors (UnityEditor.Editor[])
0x0000000024DF38B3 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Inspector\InspectorWindow.cs:352] UnityEditor.InspectorWindow:OnGUI ()
0x0000000013C368E2 (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void__this__ (object,intptr,intptr,intptr)
0x00007FF884A24EAB (mono) [c:\buildslave\mono\build\mono\mini\mini.c:4937] mono_jit_runtime_invoke
0x00007FF8849784E1 (mono) [c:\buildslave\mono\build\mono\metadata\object.c:2623] mono_runtime_invoke
0x00007FF88497E8DB (mono) [c:\buildslave\mono\build\mono\metadata\object.c:3827] mono_runtime_invoke_array
0x00007FF88493CF2F (mono) [c:\buildslave\mono\build\mono\metadata\icall.c:2857] ves_icall_InternalInvoke
0x0000000013C00217 (Mono JIT Code) (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&)
0x0000000013BFE372 (Mono JIT Code) [/Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222] System.Reflection.MonoMethod:Invoke (object,System.Reflection.BindingFlags,System.Reflection.Binder,object[],System.Globalization.CultureInfo)
0x0000000013CC428F (Mono JIT Code) [/Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115] System.Reflection.MethodBase:Invoke (object,object[])
0x0000000021AEDFC6 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\HostView.cs:187] UnityEditor.HostView:Invoke (string,object)
0x0000000021AEDEB0 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\HostView.cs:180] UnityEditor.HostView:Invoke (string)
0x0000000024DBE032 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\GUI\DockArea.cs:336] UnityEditor.DockArea:OnGUI ()
0x0000000013C368E2 (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void__this__ (object,intptr,intptr,intptr)
0x00007FF884A24EAB (mono) [c:\buildslave\mono\build\mono\mini\mini.c:4937] mono_jit_runtime_invoke
0x00007FF8849784E1 (mono) [c:\buildslave\mono\build\mono\metadata\object.c:2623] mono_runtime_invoke
0x00000001403341AF (Unity) scripting_method_invoke
0x00000001404A05DD (Unity) ScriptingInvocationNoArgs::Invoke
0x0000000141201026 (Unity) MonoBehaviourDoGUI
0x00000001411F4650 (Unity) IMGUIModule::MonoBehaviourDoGUI
0x00000001403152AA (Unity) MonoBehaviour::DoGUI
0x0000000140DB289D (Unity) GUIView::OnInputEvent
0x0000000140DB3A29 (Unity) GUIView::ProcessEventMessages
0x0000000140DB5465 (Unity) GUIView::GUIViewWndProc
0x00007FF8A7D21169 (USER32) DispatchMessageW
0x00007FF8A7D20C97 (USER32) DispatchMessageW
0x0000000140DCFC7B (Unity) RelaunchUnity
0x0000000140DD131B (Unity) WinMain
0x000000014151EF94 (Unity) read
0x00007FF8A83F8102 (KERNEL32) BaseThreadInitThunk

========== END OF STACKTRACE ===========