Parsing error during connection to server

When I attempt to connect to my 6.0.2 server on my Mac, using this:

                   var config = new Configuration()

                            .WithServers("couchbase://127.0.0.1")

                            .WithBucket("default")

                            .WithCredentials("Administrator", "password");

                    var cluster = new Cluster(config);

                    var bucket = await cluster.BucketAsync("default");

, I get an exception parsing the cluster map. The json that comes back from the server contains $HOST:XXX (where XXX is a port), and these seem not to parse, when deserializing into a BucketConfig.

is the stack trace...

NOTE: I'm completely ignorant of .NET (just recently learned how to spell it), and am running this on a Mac (which seems like an edge case too). So, YMMV on this.