I am getting this error most of the time when I submit my form. I am using Sitefinity 6.2 with ASP.NET MVC 4.0 and JQuery Mobile.
As I have Sitefinity in Hybred mode I am using the @Html.BeginFormSitefinity() command to create the form. On the Controller I have my action with the [HttpPost] attribute. The code always hits my default action on the controller with no problem. No matter what I put in the form when I submit I only get an error message on the page...never hits the HttpPost action.
I've looked around and there are many pages with fixes for the MAC failed issue, but none are working for me. I have a machine key in the web.config and I am NOT going to set enableViewStateMac to false as that is a security hole.
OK I tried working with both of the below solutions but they are both really bad. Here is what I am doing now, which is still not great, but I have Sitefinity, MVC, and JQuery Mobile all on the same page and forms are not giving me View State Exceptions anymore.
First thing is that adding data-ajax="false" is not enough, for this to work you need to disable Ajax before JQuery Mobile starts. So, to do this you need to add in this script BEFORE the JQuery Mobile File loads but after the JQuery file loads.
After doing this I then do not use the Sitefinity Begin Form, I just JQuery to change the form on the main page to have the correct action.
Together this means that there is a complete page load for each page change, and form posts use the form declared in my WebForms Master Page.