Most likely your DataObject does not put itself into its own CookieSet/Lookup. If you call setCookieSet(), or override getLookup() or getCookie(), this can happen. There are a few parts of NetBeans which will expect Node`s to be present in their own `Lookup`s and `DataObject`s to be present in theirs. It is always best to make sure they are there. For a `DataObject, the code for this is usually as simple as: