If you have ever done anything in zope you will have run across this annoying and not verry helpfull error message.
PTRuntimeError: Page Template (unknown) has errors.
I have found two instances that cause this, but in general it’s a problem with parsing the structure of your zpt document, not a specific syntax error in your tal: tags
The first cause of this error is not closing a tag (like a <li> tag). ZPT requires valid xhtml so close those tags.
The second cause can be a missing space between tag attributes. notice the lack of spacing between the name and id tag attributes below
<input name="thisfield"id="thidid">