Tidy: ... attribute ... lacks value
This is an error show when an attribute contained in a tag does not contain a value and that a value was expected. Or this can also be due to syntax error in the HTML tag.
<a> attribute href lacks value
|<a href>My Link</a>|
|<a href="my_link.html">My Link</a>|
Check the definition of the attribute. Give a value to the tag or correct the wrong/unknown tag.