How to solve ASP.Net EnableEventValidation Error

Question

I got EnableEventValidation error for redirect a page to another ASPX....

Error Message:

Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.


My ASPX Page Code:

<%@ Page Language="C#" EnableEventValidation="true" AutoEventWireup="true" CodeFile="~/jobs/Register.aspx.cs" Inherits="jobs_Register" %>


Actually Inside that .cs page i use one dropdownlist selected index changed and one button event code...


and I got this error in so many pages, if i resolve in one page i will change in anothers. Please helpme resolve this error?