I have found that only error codes that are <0 (msb bit set) will propagate up to a LV error cluster from my automation interface. Is it possible, in accordance with the COM spec, to be able to pass error codes with a positive value up to LV?
LabVIEW is able to receive positive COM errors from applications I've used. I just returned a positive 1 from a DirectX ValidMesh call and a 5500 from a failed LabVIEW server call.