Commented Unassigned: Getting "SOCKS5: General failure" error [2094]

I am working on code which connects using sftp and proxy. Following is my code snippet. I am getting "SOCKS5: General failure." error. Please help. (Using 4.0 binary)

Imports Renci.SshNet.SftpClient
.
.
.
Dim pa As New Renci.SshNet.PasswordAuthenticationMethod("<username for site>", "<password for site")

Dim connectionInfo As New Renci.SshNet.ConnectionInfo(ftpUrl, <site port number>, "<username for site>", Renci.SshNet.ProxyTypes.Socks5, "<our proxy name>", <our proxy port number>, "<my windows username>", "<my windows password", pa)

Dim sftp As New Renci.SshNet.SftpClient(connectionInfo)
sftp.Connect()
.
.
Comments: ** Comment from web user: drieseng **

Can you provide the full stack trace of the NullReferenceException you get on Connect() ?
What version of SSH.NET are you using ?