[Plugin: Special Text Boxes] Validator errors?

https://validator.w3.org/check?uri=http%3A%2F%2Fprofaneentertainment.com%2Fleague%2Fcreate-a-match%2F&charset=%28detect+automatically%29&doctype=Inline&ss=1&group=0&user-agent=W3C_Validator%2F1.2

When I do a W3C check it returns numerous errors with the plugin. Does the plugin need and update? How can I fix these problems?

https://www.ads-software.com/extend/plugins/wp-special-textboxes/