W3C html validation error

If post title name has quotes

<meta itemprop="name" content=""post title"" />

is not valid.

You need add htmlentities() to the code:

// Filter the schema item name
$item_name = apply_filters( 'comment_rating_field_pro_rating_output_build_average_rating_html_schema_title', htmlentities(strip_tags( $post->post_title )), $group );

And this code also gives an error

<label for="rating-star-1">

“The value of the for attribute of the label element must be the ID of a non-hidden form control”

And if web page doesn’t have a meta tag

itemscope itemtype="https://schema.org/WebPage"

HTML code is not valid too.