Error -10646 translates to "Cannot Load Network Adapter", the driver associated with the communications board in use. From your description of the problem, the most likely reason for this is that MacDFT 1.1 is required. Update the software, and everything should work as advertised.
The network adapter is DAL driver software, specific to MacMainFrame. It is available from DCA (formerly Avatar).
As of DAL release 1.2 all DAL releases ship with all the available network adapters. You non longer need to contact the network communications companies for the individual DAL pieces.