iControl 11.4.1/11.2 and Enterprise Manager 3.1.1

When using C and iControl 11.4.1 against an Enterprise Manager running EM v3.1.1 we are receiving the following error messages when executing the method get_devices(). An error occurred:

System.Web.Services.Protocols.SoapHeaderException: Exception caught in Management::urn:iControl:Management/EM::get_devices() Exception: Common::OperationFailed primary_error_code : 0 (0x00000000) secondary_error_code : 0 error_string : Could not retrieve the device address list at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall) at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters) at iControl.ManagementEM.get_devices() at UltimateSoftware.Automation.Modules.F5.F5Module.ListF5Devices() at UltimateSoftware.F5EnterpriseManagerConfigExporter.Program.Main(String[] args)

It is not clear how to proceed.

Any assistance would be appreciated.