I am running into Validation of viewstate MAC failed errors when trying to follow this example.
If I enter a value into the city text box and click the search button I receive the validation of viewstate MAC failed error. I have paging turned on and I noticed that if I go to a different page other than the default page #1 that the search feature appears to work fine. It is just on this initial page that it fails.
Things I have checked:
1.) There is not action value set on my masterpage <form> tag. It reads <form id="mainForm" runat="server">
2.) I enabled viewstate from Titles & Properties for the page in question
I have created custom forms in the past and have not had to generate a machine key so this feels like something else going on, but any input would be helpful.