Get connection closed error when trying to extract data from vCenter Server using C# application

I get the below error while extracting data from vCenter 5.5 Server using C# vSphere 5.5 SDK (The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.)

ERROR The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.

System.Net.WebException: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host

   at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)

   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)

   --- End of inner exception stack trace ---

   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)

   at System.Net.FixedSizeReader.ReadPacket(Byte[] buffer, Int32 offset, Int32 count)

   at System.Net.Security._SslStream.StartFrameHeader(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)

   at System.Net.Security._SslStream.StartReading(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)

   at System.Net.Security._SslStream.ProcessRead(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)

   at System.Net.TlsStream.Read(Byte[] buffer, Int32 offset, Int32 size)

   at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)

   at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)

   --- End of inner exception stack trace ---

   at System.Web.Services.Protocols.WebClientProtocol.GetWebResponse(WebRequest request)

   at Microsoft.Web.Services3.WebServicesClientProtocol.GetResponse(WebRequest request, IAsyncResult result)

   at Microsoft.Web.Services3.WebServicesClientProtocol.GetWebResponse(WebRequest request)

   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)

   at Vim25Api.VimService.RetrieveProperties(ManagedObjectReference _this, PropertyFilterSpec[] specSet)

   at vCenterTestConnect.vCenterESXHostInfo.getvCenterHostAdvancedInfo()

   at vCenterTestConnect.vCenterESXHostInfo.startExtraction()

Yje application works fine in test environment in our lab (with 2 hosts and 22 VM) but gives the above error when used in prod environment. Any help would be appreciated.