The itemprop attribute was specified, but the element is not a property of any item - Schema.org

The itemprop attribute was specified, but the element is not a property of any item - Schema.org

You should explicitly provide a type these properties (name, description, image) belong to. In Schema.org, everything is a Thing. For example: WebPage, Article or maybe BlogPosting.

<html itemscope itemtype="http://schema.org/WebPage">