Adding and Deleting data group records and ZoneRunner records via PowerShell

So I am trying to just list the resource records get_rrs and get_rrs_detailed and I am getting the following error:

An unhandled exception of type 'System.Net.WebException' occurred in System.dll

Here's the code:

Interfaces interfaces = new Interfaces();

string[] view = { "external" };

ManagementViewInfo[] views = interfaces.ManagementView.get_list();

ManagementViewZone[] viewZones = interfaces.ManagementZone.get_zone_name(view);

ManagementZoneInfo[] zoneInfo = interfaces.ManagementZone.get_zone(viewZones);

ManagementResourceRecord rr = new ManagementResourceRecord();

string[][] resourceRecords = rr.get_rrs(viewZones);

ManagementRRList[] resourceRecordsDetailed = rr.get_rrs_detailed(viewZones);

Thanks!