Method not found

Import-Module WinSCP
$UN = "USERREMOVED"
$SPW = Get-Content "C:\Projects\CheckPull\IPSFiservCredentials.txt" | ConvertTo-SecureString
$Credentials = New-Object System.Management.Automation.PSCredential -ArgumentList $UN, $SPW
$SshHostKeyFingerprint = "ssh-dss 1024 REALSTUFFREMOVED"
$IPSFiserv = "SITEREMOVED"
$sessionOption = New-WinSCPSessionOption -HostName $IPSFiserv -Protocol Sftp -SshHostKeyFingerPrint $SshHostKeyFingerprint -Credential $Credentials
$session = New-WinSCPSession -SessionOption $sessionOption
$directory = $session.ListDirectory("PATHREMOVED")
foreach ($fileInfo in $directory.Files)
{
    Write-Host ("$($fileInfo.Name) with size $($fileInfo.Length), " +
        "permissions $($fileInfo.FilePermissions) and " +
        "last modification at $($fileInfo.LastWriteTime)")
}
Remove-WinSCPSession -WinSCPSession $session