I am using updatepanel in aspx with master page content, required validation control. IN that updatepanel I have one datagrid through that I am trying to insert a row. When I click that linkbutton then is shows error like "sys.webforms.pagerequestmanagerparsererrorexception. Error code: 405" . I tried with another project this code works fine. How to overcome this. Some times error code 12031 also appear in prompt window.