Error 21919303: The item specific is missing. Add to this listing, enter a valid value, and then try again.

This error occurs when a required item specific is missing. Please go to the ItemSpecifics container and add a NameValueList container that has the missing required item specific as the NameValueList.Name value and insert the value of the item specific in the NameValueList.Value field. To see which item specifics are required for a category, you can use the getItemAspectsForCategory method.