Error: Element link is missing required attribute property

I see this error of your plugin in the serrvice of validation W3.
my web results:
http://validator.w3.org/check?uri=ganardineroenvenezuela.com.ve

Error Line 439, Column 193: Element link is missing required attribute property.
…e-schemaorg-rich-snippets/css/style.css?ver=4.0′ type=’text/css’ media=’all’ />
Attributes for element link:
Global attributes
href
crossorigin
rel
media
hreflang
type
sizes
Also, the title attribute has special semantics on this element.

how can I fix this error?. thanks

https://wordpress.org/plugins/all-in-one-schemaorg-rich-snippets/