Html5 Validation Error

hello to all.

I have cs-cart 415 and i have problem with validation in html5.

i have the error

Line 5031, Column 20:

Element ul not allowed as child of element ul in this context. (Suppressing further errors from this subtree.)

    Contexts in which element [url=""]ul[/url] may be used: Where [url=""]flow content[/url] is expected. Content model for element [url=""]ul[/url]: Zero or more [url=""]li[/url] and [url=""]script-supporting[/url] elements.

    Any idea?

    Any help is accepted
    thanks in advance