My SEO module shows "missing schema markup" in some tools. Is this a problem?

A missing markup warning means the tool did not find the schema type or required field on that URL. In Schema Revolution, first check that the schema type is enabled for that page type, then compare the module preview with the final page source after cache is cleared, and finally test the live URL in Google's Rich Results Test or Schema.org's validator.

The module builds JSON-LD based on the detected page type. Depending on configuration it can output Organization and WebSite on the homepage, BreadcrumbList on non-home pages, Product schema on product pages, CollectionPage for categories, and Article for CMS pages. Product schema can include name, URL, description, SKU, GTIN, MPN, brand from the configured catalogue source, images, condition, offers, availability, shipping details, return policy, ratings, reviews, weight and category data when the shop has that data available.

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Example product",
  "url": "https://example.com/product.html",
  "description": "Short product description",
  "sku": "REF-123",
  "gtin13": "1234567890123",
  "offers": {
    "@type": "Offer",
    "price": "29.99",
    "priceCurrency": "EUR",
    "availability": "https://schema.org/InStock"
  }
}

If Google reports missing fields, compare three things: the module preview, the final HTML source after PrestaShop and external caches are cleared, and the live URL fetched by the test tool. A field can be absent because the schema type is disabled, the page detector does not identify the page as expected, the product lacks source data such as brand or GTIN, cached HTML is still being served, or another theme/module changes the final output.

Be careful with the cleanup options. They are intended to remove older microdata and duplicate JSON-LD, but the current JSON-LD cleanup preserves only scripts marked with <!-- mprschema -->, while the module's header output is unmarked. With clean_existing_jsonld enabled, including its default state, the cleanup can remove the module's own schema from the final HTML. If tools show missing schema, disable/fix JSON-LD cleanup or add the expected marker before assuming another module is at fault.

In the module configuration, open Schema Revolution > Configuration > Schema Types. Enable the missing type there: Product Schema, Organization Schema, WebSite Schema, Breadcrumb Schema, Category Schema or CMS Article Schema, depending on the URL being tested.

If the schema exists in preview but disappears from the final HTML, disable Remove Existing JSON-LD in the same Schema Types tab while testing. That option removes unmarked application/ld+json scripts from the page before output, so it is the first setting to check when validators report that all JSON-LD is missing.