OPC Net API throws exception|Classic OPC: DA, A&E, HDA, XML-DA, etc.|Forum|OPC Foundation

Hello, I am trying to use the OPC Net API v2.1 for connecting to OPC server. When I try to connect to the server, connect method throws exception: E_NOTSUPPORTED IOPCServer.AddGroup. I don't know the reason of this problem. The OPC server I am connecting to is made by SST (Molex) to communicate with profibus simulation card. I have tried to connect to another OPC server (Matrikon OPC simulation server) and it works fine.

Does anyone have any solution for this problem? Thank you.