In order to advertise your products on Facebook, you must provide at least one of the following identifiers: brand name, Global Trade Identification Number (GTIN) or Manufacturer Part Number (MPN). If you are seeing this error, it's because your products do not have at least one of these identifiers.
To fix this error, please go directly into your ecommerce store, and update any products you are advertising to include this information. We'll automatically sync new product data every 24 hours. Once the missing universal identifier has been updated for your products, this error should disappear within 1-2 business days/