Setting ViewStateUserKey gives me a “Validation of viewstate MAC failed” error

Question

I have the following in my BasePage class which all my ASPX pages derive from:

protected override void OnInit(EventArgs e)
{
    base.OnInit(e);         


        

Answer 1

I fixed it for now by changing the code to:

protected override void OnInit(EventArgs e)
{
    base.OnInit(e);

    if (User.Identity.IsAuthenticated)
        ViewStateUserKey = User.Identity.Name;
}