Steps to reproduce:
1.Click on the "Edit" button
2.Insert a reference with no content.
3.Save the page
The error message that appears on the page is "Cite error: The opening <ref> tag is malformed or has a bad name" where as
when you edit a reference (not first time insert) to an empty content the error message that appears is "Cite error: There are <ref> tags on this page without content in them"
The later one is more understandable for a user.So maybe we can change the message to the later one.