Opening the State Machine Editor window will throw a NullReferenceException error, then when you close the editor window Unity crashes.
Here is the error:
NullReferenceException: Object reference not set to an instance of an object
UOP1.StateMachine.Editor.TransitionTableEditorWindow.CreateListView () (at Assets/_Project/Scripts/Editor/TransitionTableEditorWindow.cs:86)
UOP1.StateMachine.Editor.TransitionTableEditorWindow.Update () (at Assets/_Project/Scripts/Editor/TransitionTableEditorWindow.cs:77)
UnityEditor.HostView.SendUpdate () (at :0)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at :0)