Error 21919305: Has too many values.

This error occurs when you have exceeded the upper threshold of separate values that can be specified for one item specific name called out in the error message, or if that item specific only supports one value. It can vary by marketplace and category, but the upper threshold of values allowed for one item specific is 30. Many item specifics only support one value, so it is a good idea to use the getItemAspectsForCategory method, look for that item specific in the response, and make sure the value of the aspectConstraint.itemToAspectCardinality field is MULTI and not SINGLE. Please revisit your ItemSpecifics.NameValueList container for that item specific name and remove one or more values based on what you discover.