In previous versions of ASP.NET, URLs were limited to 260 characters in length (based on the NTFS file-path limit). But in ASP.NET 4.0 developers have the option of increasing or decreasing the length of URLs by using the new maxRequestPathLength and maxQueryStringLength. maxRequestPathLength - To allow longer or shorter paths (the portion of the URL that does not include protocol, server name, and query string), modify the maxRequestPathLength attribute. maxQueryStringLength - To allow longer or shorter query strings, modify the value of the maxQueryStringLength attribute. For example.. <httpRuntime maxRequestPathLength="360"...