Created Unassigned: System.InvalidOperationException: Server string is null or empty [1935]

I have utilized your Library. Which Is working absolutely fine for downloading and uploading files on SFTP server.

But, Sometimes it gives me an error (__System.InvalidOperationException: Server string is null or empty__ at __Renci.SshNet.Session.Connect() at Renci.SshNet.BaseClient.Connect()__ ) during connection to the SFTP using Renci.SSH.

I don't understand what is the problem.

If there is an issue in my implementation then I should have received error all the time but this is not the case. All the time this is working fine but some times it starts giving me an error.

Below is the code which I used to connect to the SFTP server :

```
var sftpClient = new SftpClient(
[SftpHostAddress],
[SftpHostPort],
[SftpUserName],
[SftpPassword]);

sftpClient.OperationTimeout = [OperationTimeOut];
sftpClient.ConnectionInfo.Timeout = [ConnectionTimeOut];

sftpClient.Connect();

// My Work goes here

// Dispose object
if (null != sftpClient)
{
sftpClient.Disconnect();
sftpClient.Dispose();
sftpClient = null;
}
```

__Library version info :__

__File Version :__ 2013.4.7.0
__Product Version :__ 2013.4.7
__Size :__ 411kb
__Product Name :__ SSH.NET