Passing credential to New-Object iControl.Interfaces

I think your problem is with the Get-Credential call. That will return a PSCredential object with UserName (String) and Password (SecureString) members. You are treating the SecureString as a regular string when passing that in. Odds are the error occurs there. Try converting the password into a clear text string before calling initialize.

$creds = Get-Credential;
$user = $creds.Username;
$pass = $creds.GetNetworkCredential().Password;

Here's an article on dissecting the SecureString

http://blogs.technet.com/b/heyscriptingguy/archive/2013/03/26/decrypt-powershell-secure-string-password.aspx

Hope this helps...

-Joe