CAT_SALE_PRICE_EQUAL_OR_GREATER_THAN_PRICE is returned when sale_price is greater than or equal to price. Snap suppresses misleading sale labeling, so the sale value must always be strictly lower than the regular value.
Snap Catalog 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.