OPC DA: Unable to cast COM object of type 'System.__ComObject' to interface type 'OpcRcw.Comn.IOPCServerList2'|Classic OPC: DA, A&E, HDA, XML-DA, etc.|Forum|OPC Foundation

I am trying to connect to an instance of Graybox Simulator on a server, but it is failing with the following message:

System.InvalidCastException: Unable to cast COM object of type 'System.__ComObject' to interface type 'OpcRcw.Comn.IOPCServerList2'. 

This operation failed because the QueryInterface call on the COM component for the interface with IID '{9DD0B56C-AD9E-43EE-8305-487F3188BF7A}' failed due to the following error: 

No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).
   at Opc.Server.Connect(URL url, ConnectData connectData)
   at Opc.Da.Server.Connect(URL url, ConnectData connectData)
   at Opc.Server.Connect()

Server info:

Windows Server 2012 R2 Standard

64-bit Architecture

URL I'm trying to connect to:

"opcda://localhost/Graybox.Simulator"

I can browse the OPC server just fine using Matrikon OPC Explorer:

I've tried playing with the DCOM settings. I've tried installing, uninstalling, and re-installing multiple versions of .NET API Redistributables and Core Components.

Running out of ideas. 

Any suggestions?

Thanks.