The Comparison Shopping Service (CSS) that these products are associated with doesn’t currently meet the eligibility requirements to advertise in this target country. In particular, the CSS’s website does not show products from at least 50 distinct merchant domains in this country. Your products in this target country will not be able to serve unless the CSS meets the eligibility criteria.
If you are a merchant: Reach out to the CSS you are working with to resolve this issue.
If you are a CSS: Ensure that you have products from a sufficient number of merchants on your website for each country where you want to show Shopping ads. Check Merchant Center’s “CSS Overview” in your main CSS multi-client account to see the number of merchants you represent in each country. Add any merchants that may be missing.