Send all *.csv files in directory to SFTP Server using Script Task in SSIS c#

Question

https://winscp.net/eng/docs/library_ssis

I am trying to follow this script to eventually get all csv files from a directory on our local network uploaded to an SFTP server. I don't get any errors when I build/rebuild the script task, but when I run it, immediately fails with "Exception has been thrown by the target of an invocation." Nothing shows up in the log at all. I am trying to get at least one file to upload by itself to make sure the upload piece is working. Then I want to modify it to upload all csv files in the same directory. Any tips or pointers in how to troubleshoot this will be greatly appreciated.

    [SSISScriptTaskEntryPoint]
    public partial class ScriptMain : VSTARTScriptObjectModelBase
    {
        public void Main()
        {
            // Setup session options
            SessionOptions sessionOptions = new SessionOptions
            {
                Protocol = Protocol.Sftp,
                // To setup these variables, go to SSIS > Variables.
                // To make them accessible from the script task, in the context menu of the
                // task, choose Edit. On the Script task editor on Script page,
                // select ReadOnlyVariables, and tick the below properties.
                HostName = (string)Dts.Variables["$Project::prmHost"].Value,
                UserName = (string)Dts.Variables["$Project::prmUser"].Value,
                Password = (string)Dts.Variables["$Project::prmPassword"].Value,
                SshHostKeyFingerprint = (string)Dts.Variables["$Project::prmFingerprint"].Value,
                PortNumber = Convert.ToInt32(Dts.Variables["$Project::prmPort"].Value)
            };

            try
            {
                using (Session session = new Session())
                {
                    // If WinSCP .NET assembly has been stored in GAC to be used with SSIS,
                    // you need to set path to WinSCP.exe explicitly.
                    // This is not needed if you have subscribed AppDomain.AssemblyResolve event
                    // and the WinSCP.exe is in the same location as WinSCPnet.dll.
                    //session.ExecutablePath = @"C:\winscp\winscp.exe";
                    session.SessionLogPath = Dts.Variables["$Project::prmLogFileName"].Value.ToString();

                    // Connect
                    session.Open(sessionOptions);

                    string remotePath = Dts.Variables["$Project::prmPath"].Value.ToString();
                    string localPath = Dts.Variables["$Project::prmLocalPath"].Value.ToString() + "etrainingusers_0.csv";

                    // Upload files
                    TransferOptions transferOptions = new TransferOptions();
                    transferOptions.TransferMode = TransferMode.Binary;

                    TransferOperationResult transferResult = session.PutFiles(
                       localPath, remotePath, false, transferOptions);

                    // Throw on any error
                    transferResult.Check();

                    // Print results
                    bool fireAgain = false;
                    foreach (TransferEventArgs transfer in transferResult.Transfers)
                    {
                        Dts.Events.FireInformation(0, null,
                            string.Format("Upload of {0} succeeded", transfer.FileName),
                            null, 0, ref fireAgain);
                    }
                }

                Dts.TaskResult = (int)DTSExecResult.Success;
            }
            catch (Exception e)
            {
                Dts.Events.FireError(0, null,
                    string.Format("Error when using WinSCP to upload files: {0}", e),
                    null, 0);

                Dts.TaskResult = (int)DTSExecResult.Failure;
            }
        }
    }

This is the currently working code to upload one single .csv file.

#region Namespaces
using System;
using System.Windows.Forms;
using System.IO;
using System.Reflection;
using Microsoft.SqlServer.Dts.Runtime;
using Microsoft.SqlServer.Dts.Tasks.ScriptTask;
using WinSCP;
#endregion

namespace ST_4977fa724bbb4816bfe3d3c8f2376a79
{
    [Microsoft.SqlServer.Dts.Tasks.ScriptTask.SSISScriptTaskEntryPointAttribute]

    public partial class ScriptMain : Microsoft.SqlServer.Dts.Tasks.ScriptTask.VSTARTScriptObjectModelBase
    {

        private const string LoadingLog = @"C:\winscp\elearningupload.log";
        private const string AssemblyPath = @"C:\winscp\WinSCPnet.dll";

        static ScriptMain()
        {
            DebugLoading("Setting up assembly resolve handler");
            AppDomain.CurrentDomain.AssemblyResolve += AssemblyResolve;
        }

        private static void DebugLoading(string message)
        {
            message = DateTime.Now.ToLongTimeString() + ": " + message + Environment.NewLine;
            // Uncomment to debug assembly loading issues
            File.AppendAllText(LoadingLog, message);
        }

        private static Assembly AssemblyResolve(object sender, ResolveEventArgs args)
        {
            try
            {
                DebugLoading($"Resolving assembly {args.Name}");
                string name = new AssemblyName(args.Name).Name;
                DebugLoading($"Assembly name {name}");
                if (name.Equals("WinSCPnet", StringComparison.InvariantCultureIgnoreCase))
                {
                    DebugLoading($"Loading {name} from {AssemblyPath}");
                    Assembly assembly = Assembly.LoadFile(AssemblyPath);
                    DebugLoading("Loaded");
                    return assembly;
                }
                DebugLoading("Not WinSCPnet");
                return null;
            }
            catch (Exception e)
            {
                DebugLoading($"Exception: {e}");
                throw;
            }
        }
        public class AppException : Exception
        {
            public AppException(String message) : base(message)
            { }

            public AppException(String message, Exception inner) : base(message, inner)
            { }
        }

        public void Main()
        {
            SessionOptions sessionOptions = new SessionOptions
            {
                Protocol = Protocol.Sftp,
                HostName = (string)Dts.Variables["$Project::prmHost"].Value,
                UserName = (string)Dts.Variables["$Project::prmUser"].Value,
                Password = (string)Dts.Variables["$Project::prmPassword"].Value.ToString(),
                SshHostKeyFingerprint = (string)Dts.Variables["$Project::prmFingerprint"].Value,
                PortNumber = Convert.ToInt32(Dts.Variables["$Project::prmPort"].Value)
            };

            try
            {
                using (Session session = new Session())
                {
                    session.ExecutablePath = @"C:\winscp\winscp.exe";
                    session.SessionLogPath = Dts.Variables["$Project::prmLogFilePath"].Value.ToString();
                    //session.SessionLogPath = @"C:\winscp\elearningupload.log";

                    //Directories
                    string fname = Dts.Variables["$Project::prmFilename"].Value.ToString();
                    string locpath = Dts.Variables["$Project::prmLocalPath"].Value.ToString(); //This is the local directory
                    string path = Dts.Variables["$Project::prmPath"].Value.ToString(); //This is the desired remote directory
                    string fullname = locpath + fname;

                    // Connect
                    session.Open(sessionOptions);

                    // Upload files
                    TransferOptions transferOptions = new TransferOptions();
                    transferOptions.TransferMode = TransferMode.Binary;
                    transferOptions.PreserveTimestamp = false;
                    var permissions = new FilePermissions { Octal = "0750" };
                    transferOptions.FilePermissions = permissions;
                    TransferOperationResult transferResult = session.PutFiles(@fullname, @path, false, transferOptions);

                    // Throw on any error
                    transferResult.Check();

                    // Print results
                    bool fireAgain = false;
                    foreach (TransferEventArgs transfer in transferResult.Transfers)
                    {
                        Dts.Events.FireInformation(0, null,
                            string.Format("Upload of {0} succeeded", transfer.FileName),
                            null, 0, ref fireAgain);
                    }
                }
                Dts.TaskResult = (int)ScriptResults.Success;
            }

            catch (AppException e)
            {
                //Raise Error event
                Dts.Events.FireError(0, "Script Task", "Error", string.Empty, 0);
                if (e.InnerException != null)
                    Console.WriteLine("Inner exception: {0}", e.InnerException);

                Dts.Events.FireError(0, null,
                string.Format("Error when using WinSCP to upload files: {0}", e),
                null, 0);

                Dts.TaskResult = (int)DTSExecResult.Failure;
            }


        }

        #region ScriptResults declaration
        enum ScriptResults
        {
            Success = Microsoft.SqlServer.Dts.Runtime.DTSExecResult.Success,
            Failure = Microsoft.SqlServer.Dts.Runtime.DTSExecResult.Failure
        };
        #endregion
    }
}