SharePoint - Configure managed accounts error "object reference not set to an instance of an object"

Open SharePoint 2010 Management Shell (Programs > Microsoft SharePoint...)

$ma=Get-SPManagedAccount -Identity "\"
$ma.AutomaticChange=$false
$ma.Update()

Original source...
http://social.technet.microsoft.com/Forums/sharepoint/en-US/406f1817-d687-49d7-9691-26e487fb5577/configure-managed-accounts-object-reference-not-set-to-an-instance-of-an-object-error?forum=sharepointadminprevious