You don't have access to the local Windows Registry, so the client fails to convert the server's ProgID to CLSID. Make sure you run the application with enough privileges in there, i.e. that you are an Administrator user.
Alternatively, you can just configure the connection using the server's CLSID, so you will not need the registry.
An OPC client should actually use the OpcEnum service running on the server computer to do the ProgID to CLSID conversion. Perhaps the service is not available or Utgard only tries the registry (I do not know Utgard myself). If you don't have the server installed on the client machine, the registry-based ProgID to CLSID conversion will fail anyway, since that information is not available in the local Windows Registry. The worst case is that Utgard will try to open the remote Windows Registry, which only rarely succeeds (or you need to ensure that it's enabled separately).
Note that as I do not know Utgard, I am just guessing which strategies it is attempting. Nevertheless, using CLSID only will bypass the whole conversion part, which is your problem.
E: Considering that your other client can connect without a problem, I suspect that Utgard does not try to use OpcEnum at all.