We're seeing this on a GetCustomerProfile call through the .NET SDK as of this morning. 

  "exceptionMessage": "Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.",
    "exceptionType": "System.IO.IOException",
    "stackTrace": "   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)\r\n   at System.Net.FixedSizeReader.ReadPacket(Byte[] buffer, Int32 offset, Int32 count)\r\n   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)\r\n   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)\r\n   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)\r\n   at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)\r\n   at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)\r\n   at System.Net.TlsStream.CallProcessAuthentication(Object state)\r\n   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)\r\n   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)\r\n   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)\r\n   at System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)\r\n   at System.Net.TlsStream.Write(Byte[] buffer, Int32 offset, Int32 size)\r\n   at System.Net.PooledStream.Write(Byte[] buffer, Int32 offset, Int32 size)\r\n   at System.Net.ConnectStream.WriteHeaders(Boolean async)",

I just also updated my sdk version, to make sure it was not that. 

This was working previous to today without any flaws or issues.

Thanks,

Jarrod Henry