eventvalidation

We have installed .net 4.5 Framework in one of our web servers. Our applications are targeted for .net 4.0 and run off multiple servers behind a load balancer. After the installation we get the following error message for some POST requests error_name=System.ArgumentException error_message=Invalid postback or callback argument. Event validation is enabled using 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

I know this is a very debated topic, and usually when you are thinking about this as a solution you might want to rethink your UI logic. I know I can pass validation using ClientScriptManager.RegisterForEventValidation. But, I'd really like to know. Is it possible to remove event validation for a single control? Is there a way work around for this? I'm modifying a DropDownList, from the client side after it's rendered. The short answer to your question is: No, there is no way to do this. You must disable EventValidation for the entire page. There are various workarounds... If you really don't

I have created an item swapper control consisting in two listboxes and some buttons that allow me to swap items between the two lists. The swapping is done using javascript. I also move items up and down in the list. Basically when I move the items to the list box on the right I store the datakeys of the elements (GUIDs) in a hiddenfield. On postback I simply read the GUIDs from the field. Everything works great but on postback, I get the following exception: Invalid postback or callback argument. Event validation is enabled using in configuration or <%@ Page EnableEventValidation="true" %> in