description Learn more about: .ERRNDEF title .ERRNDEF ms.date 12/17/2019 f1_keywords .ERRNDEF helpviewer_keywords .ERRNDEF directive ms.assetid 9fab57bb-02ad-486f-b46d-bcd23980f00d .ERRNDEF Generates an error if name has not been defined. Syntax .ERRNDEF name ⟦, message⟧ See also Directives Reference MASM BNF Grammar