Hi<BR><BR>I have an aspx page which has a datagrid and also includes a header page and a sidebar page.<BR><BR>When I load the page it looks fine but when I click on a column to sort it this error happens:<BR><BR>The View State is invalid for this page and might be corrupted.<BR><BR>I have tried to change the enableViewState and enableViewStateMAC to both true and false, but is has no effect.<BR><BR>This page used to be an include page, so the only html code was <BR>a form and a datagrid inside the form. Then the sorting worked.<BR><BR>So, after I changed the page from a include page to a complete html page the sorting doesn&#039;t work.<BR><BR>Does anyone have any idea why this happens?