每次运行都会报这个错误

CreateInstanceFromType is not allowed to be called from a ScriptableObject constructor (or instance field initializer), call it in OnEnable instead. Called from ScriptableObject 'BehaviorDesignerWindow'.
See "Script Serialization" page in the Unity Manual for further details.
UnityEngine.ScriptableObject:CreateInstance()
BehaviorDesigner.Editor.BehaviorDesignerWindow:.ctor()

是为什么呀？