If your product schema is returning problems you’re about to must get a little bit more forensic to determine why. But, You will find a silver lining. You don’t must normally get started with a blank slate when creating a custom Schema. You should utilize the Highly developed Schema Editor https://www.presta-addons-modules.com/en/opencart-seo-automatic-google-rich-snippets-json-ld-integration-opengraph-twitter-tags-schemaorg.html