BadNodeIdUnknown when trying to resolve method argument type|OPC UA Implementation: Stacks, Tools, and Samples|Forum|OPC Foundation

Hi,

I am writing a generic client application that connects to a server with a analyser device using the ADI Information Model. I am basing the server and client code on UA-Standard samples. I am hoping that the client application only needs to know that an analyser device of some kind exists in the server address space.

A sub component of the device has a method that has 3 input arguments. Digging into the inputArgument nodes I get the Opc.Ua.Argument.DataType. Two of them are a system data type (therefore in namespace 0) and I've been using DataTypes.GetSystemType to get the system type. When it's not in Namespace 0 but instead in ADI namespace I am getting BadNodeIdUnknown when trying to Session.FetchReference or Session.ReadDisplayName etc. I am trying to browse the type or even getting it's BrowseName would be a start.  

The NodeId is correct and the namespace is known to the client code so I am thinking it's an issue with the server? Any ideas? I understand for Part 3 4.5.1 that it might be normal that 'well-known'  type definitions (such as ADI) are not in the server address space but not sure that this is related to my issue. 

Any help appreciated.