Application connecting to FTP Client Issue

Hello,
I am working on a C# application which connects to FTP client to upload and download files to and from the FTP server.
When I run the application, I receive "COMException occured" error. Error HRESULT E_Fail has been returned from a call to a COM component. The error code is -2147467259.
Here the code where the error occured:
try
                {
                    int connStat = transferEngineConnection.Connect();
                    transferEngineConnection.set_Option("CleanupAsync", 1);
                    transferEngineConnection.set_Option("ThrowError ", 1);
                    transferEngineConnection.set_Option("AutoCloseMethod ", 1);
                    transferEngineConnection.set_Option("AutoCloseDelay  ", 1);

                    logger.Info("Connection Status returned: " + connStat.ToString());
                    return true;
                }
                catch(Exception ex)
                {
                    logger.Info("Connect Call Failed for CuteFTP " + ex.Message + ex.StackTrace);
                    return false;
                }
__________________________________________________________________________________________________________
System.Runtime.InteropServices.COMException occurred
  Message="Error HRESULT E_FAIL has been returned from a call to a COM component."
  Source="Interop.CuteFTPPro"
  ErrorCode=-2147467259
  StackTrace:
       at CuteFTPPro.TEConnectionClass.Connect()
       at NCR.ICCSGateway.ConnectionManager.Connect(TEConnection transferEngineConnection, String userName, String password, String server, String port, String localPath, String remotePath) in D:\NCR.ICCS.Gateway\NCR.ICCS.Gateway.SourceCode\ICCS_Gateway\ICCS_TransferGateway_Component\ICCS_Gateway_UserInterface\ConnectionManager.cs:line 500
  InnerException:

I am using CuteFTP 8 professional.

Thanks