I checked the request with a simple script in ac20&21 – it works the same way, gives a warning instead of just returning zero… For me it seems to be a bug, I add it to our bug database, to eliminate the warnings from attribute checking requests (it seems other similar requests are affected too…). If this problem is more than a “useless warning” in your objects, please send me some details in mail, to be able to raise the issue’s priority.
Gergely Fehér
Team Leader, Library Team
GRAPHISOFT SE