Crashing the middle tier using CC2

Consider code below to connect to a socket and read data:
Declare variables:

CC2
Automation
'Navision Communication Component version 2'.CommunicationComponent


SBA
Automation
'Navision Socket Bus Adapter'.SocketBusAdapter


OutMsg
Automation
'Navision Communication Component version 2'.OutMessage

InMsg
Automation
'Navision Communication Component version 2'.InMessage

OutS
OutStream

InS
Instream

IF ISCLEAR(CC2) THEN
 CREATE(CC2);
 IF ISCLEAR(SBA) THEN
 CREATE(SBA);

 CC2.AddBusAdapter(SBA, 0);
 OutMsg:= CC2.CreateoutMessage('Sockets://100.100.100.57:5000');

 OutS:= OutMsg.GetStream();
 OutMsg.SendWaitForReply(0);
 InMsg:= OutMsg.SendWaitForReply(2000);

IF (ISCLEAR(InMsg)) THEN BEGIN
  MESSAGE('error');
END ELSE BEGIN
   InS:= InMsg.GetStream();
    InS.READ(txt);
    MESSAGE(txt);
END;

This code works in classic. In RTC it crashes the middletier service at the InS.READ line with

Type: System.NotImplementedException
Message: The method or operation is not implemented.
StackTrace:
     at Microsoft.Dynamics.Nav.Runtime.NavApplicationMethod.InvokeMethod(Object obj, String methodName, Object[] args)
     at Microsoft.Dynamics.Nav.Service.NSField.ActionField(NavConnection con)
     at Microsoft.Dynamics.Nav.Service.NSField.Action(NavConnection connection)
     at Microsoft.Dynamics.Nav.Service.NSService.<>c__DisplayClass21.<ActionField>b__20(Connection connection)
     at Microsoft.Dynamics.Nav.Service.NSService.ExecuteOperation[T](String operationName, ServiceOperation`1 operation, Connection connection, Boolean revertLanguageChanges, WindowsIdentity impersonationIdentity)
Source: Microsoft.Dynamics.Nav.Ncl
----------------------------------
Type: System.Reflection.TargetInvocationException
Message: Exception has been thrown by the target of an invocation.
StackTrace:
     at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
     at System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
     at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
     at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
     at Microsoft.Dynamics.Nav.Runtime.NavApplicationMethod.InvokeMethod(Object obj, String methodName, Object[] args)
Source: mscorlib
----------------------------------
Type: System.NotImplementedException
Message: The method or operation is not implemented.
StackTrace:
     at System.Runtime.InteropServices.ComTypes.IStream.Seek(Int64 dlibMove, Int32 dwOrigin, IntPtr plibNewPosition)
     at Microsoft.Dynamics.Nav.Runtime.NavStreamProvider.ComStream.Seek(Int64 offset, SeekOrigin origin)
     at Microsoft.Dynamics.Nav.Runtime.NavInStream.Microsoft.Dynamics.Nav.Runtime.INavStreamReader.ReadByte()
     at Microsoft.Dynamics.Nav.Runtime.ALStream.ReadBytes(INavStreamReader reader, DataError dataError, Int32 length, ReadOptions readoptions)
     at Microsoft.Dynamics.Nav.Runtime.ALStream.ALRead(INavStreamReader reader, DataError dataError, NavText& value, Int32 length)
     at Microsoft.Dynamics.Nav.Runtime.ALStream.ALReadNavValue(INavStreamReader reader, DataError dataError, INavValueMetadata metadata, NavValue& value, Int32 length)
     at Microsoft.Dynamics.Nav.Runtime.ALStream.ALRead[T](INavStreamReader reader, DataError dataError, ByRef`1 passByRef, Int32 length)

Any idea why this is happening?