title: Invalid postback or callback argument. Event validation is enabled using in configuration or <%@ Page EnableEventvalidation =”true” %>
body: <p>I am getting the below detailed error:</p>
  
  <p>Invalid postback or callback argument. Event validation is enabled using in configuration or &lt;%@ Page EnableEventvalidation =”true” %> in a page. For security purpose, this feature verifies that arguments to postback or callback events originate from the server that originally rendered them. </p>
  
  <p>I am having a webpart page with a webpart where i do have a UPdatePanel and a button Upon Button click i  am getting this error.</p>
  
  <p>the same package(wsp) which we are using in one of our environment is working fine and the same is not working in another environment.</p>
  
  <p>Help in this is highly appreciable.</p>