“Cannot execute script because the script entry point is invalid” error in script task in SSIS

Question

I am trying to upload files from my local folder to SFTP using SSIS Script Task. On replicating the script from https://winscp.net/eng/docs/library#csharp I get an error

Error: Cannot execute script because the script entry point is invalid.

Below is the complete script:

using System;
using System.Data;
using Microsoft.SqlServer.Dts.Runtime;
using System.Windows.Forms;
using WinSCP;

namespace ST_1ae95a63b20641ffb8ed1769503e2841
{
    [Microsoft.SqlServer.Dts.Tasks.ScriptTask.SSISScriptTaskEntryPointAttribute]
    public partial class ScriptMain : Microsoft.SqlServer.Dts.Tasks.ScriptTask.VSTARTScriptObjectModelBase
    {
        #region Help:  Using Integration Services variables and parameters in a script
        class upload
        {
            public static int Main()
            {
                try
                {
                    SessionOptions sessionOptions = new SessionOptions
                    {
                        Protocol = Protocol.Sftp,
                        HostName = "a.com",
                        UserName = "btest",
                        Password = "c",
                        SshHostKeyFingerprint = "ssh-rsa 2048 avc",
                    };

                    using (Session session = new Session())
                    {
                        // Connect
                        session.Open(sessionOptions);

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

                        TransferOperationResult transferResult;
                        transferResult =
                            session.PutFiles(@"d:\abc\efdg\*", "/cvf/pqr/", false, transferOptions);

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

                        // Print results
                        foreach (TransferEventArgs transfer in transferResult.Transfers)
                        {
                            Console.WriteLine("Upload of {0} succeeded", transfer.FileName);
                        }
                    }

                    return 0;
                }
                catch (Exception e)
                {
                    Console.WriteLine("Error: {0}", e);
                    return 1;
                }
            }
        }
    }
}

I would appreciate if someone can help me with this error.

Answer 1

As WinSCP example for SSIS shows , the signature should be like:

[AddIn("ScriptMain", Version = "1.0", Publisher = "", Description = "")]
public partial class ScriptMain : VSTARTScriptObjectModelBase
{
    public void Main()
    {
        // ...
    }
}

Particularly, remove the nested upload class.

Answer 2

According to this Msdn article :

Make sure in the script task's editor, the Script page's Entry Point property is set to ScriptMain.

Additional Informations

• ScriptTask.EntryPoint Property