Structured Data Linter error | WordPress.org

I saw the message “Run Structured Data Linter to validate structured data” in PageSpeed Insights.

When I try my content here, I get the following message:

error NoMethodError: undefined method `property?’ for #http://ogp.me/ns#updated_time>

Example: http://linter.structured-data.org/?url=https:%2F%2Fwww.ufukgazetesi.net%2Fbeyoglunda-yks-deneme-sinavi.html

Is this a mistake?

This error disappears when I delete the plugin.

The page I need help with: [log in to see the link]