Price value is missing the ISO 4217 currency code (e.g. '15.00' with no 'USD').
Meta Commerce Manager's product schema has format and value rules per attribute. This issue is typically: missing a required attribute for the category, an invalid enum value (e.g., 'XL' submitted where 'M, L, XL' is the valid set), out-of-range numbers, or attributes that conflict across the feed.