3b704f88_Local_Real_Estate_API___Zillow__Description
[Error code] 501 [Resolution] Make sure to provide at least either an rid parameter or zip or city or state parameter. Neighborhood and state parameters without a city parameter will not work. Also check to make sure all parameter names are lowercase (i.e. City=Seattle is invalid, city=Seattle is valid) [Description] 
Missing parameters
Local Real Estate API | Zillow
Description