on your login page, you have the following code that is locking the code above the doctype tag:
<!-- InstanceBegin template="/promotables/templates/maintemplate.dwt.php" codeOutsideHTMLIsLocked="true" -->
you will need to use a text editor to change that to:
<!-- InstanceBegin template="/promotables/templates/maintemplate.dwt.php" codeOutsideHTMLIsLocked="false" -->
to unlock the code above the doctype to prevemnt the error.