Indy 10 raising an unwanted exception

Question

I have a client/server app developed in delphi XE that uses TIdTcpClient (Indy10) to communicate to each other. All works fine most the time, the only issue is when I kill the server side the client is raising an exception that somehow raises all the way to the user, it first show my custom exception:

and after it display an error dialogue in blank as below:

This is the code that should override the original exception, the dialog I create display and the other dialog (the image above) display just after.

constructor EtvdNTierTcpException.Create(const AException: Exception);
const
 error = 'error message';

var
  AIdSocketError: EIdSocketError;
  sMessage, sConnectionPoint: string;
begin
  if AException is EIdSocketError then
  begin
    AIdSocketError := AException as EIdSocketError;
    if StvdDefaultSession.tvdConnectionPoint = cpSqlProxy then
      sConnectionPoint := FtvdNTierSqlProxy
    else
      sConnectionPoint := FtvdNTierSqlServer;
    case AIdSocketError.LastError of
      // 10054: Connection reset by peer
      10054: self.Message := ExtractFileName(application.exename) + error +  DateToStr(Now) + ' ' + TimeToStr(Now) + ' (' + AIdSocketError.ClassName + ')' + 'Connection for dataset fail at(10054)';
      // 10061: Connection refused
      10061: self.Message := ExtractFileName(application.exename) + error +  DateToStr(Now) + ' ' + TimeToStr(Now) + ' (' + AIdSocketError.ClassName + ')' + 'Connection for dataset fail at(10061)';
      else
        self.Message := error +  DateToStr(Now) + ' ' + TimeToStr(Now) + ' (' + AIdSocketError.ClassName + ')' + 'Connection for dataset fail at('+IntToStr(AIdSocketError.LastError)+')';
    end;
  end;
  inherited;
end;

I try to use CheckForGraceFulDisconnect(false); but it does not make any difference, any ideas in how to stop Indy displaying this error?

This is how the exception above get raised:

function TtvdNTierDataSet.tvdStmtExecute(const AStmt: string): Boolean;
begin
  try
      tvdStmtExecute := False;
      // check we are still connected to the server
      if tvdSession.tvdConnect then
      begin
        tvdStmtExecute := True;
        // write the SQL Statement to the server
        tvdWriteOutput;
      end;
  except
    on E: Exception do
    begin
      // re-raise the exception
      raise EtvdNTierTcpException.Create(E);
    end;
  end;
end;

Answer 1

if the exception is not of type EIdSocketError you get an empty Exception Dialog.

if AException is EIdSocketError then