Failed to load CustomEditor inspected type

I had an error like this when play my own level

Can't load custom inspector SunShaftsEditor because the inspected type is null UnityEditor.CustomEditorAttlibutes:FindCustomEditorType(Object)

and can't use any Effects. somebody know how to fix it ?

Delete or reimport …Your Super Project - Assets - Standard Assets - Editor \

Whatever is in that folder causes this error. Probably bad scripts.