[VE][106] schema and xhtml

Validating http://www.lomasbuscado.net/
Error [106]: "X is not a member of a group specified for any attribute"


I add schema (http://schema.org/) tags in xhtml and the validating said error like :

<ul class="navigation" itemscope itemtype="http://schema.org/CreativeWork"> "itemscope" is not a member of a group specified for any attribute  How can I do ?