Page_Init is an event fired by OnInit, so when you call OnInt, it calls
Page_Init.
you only need to call base.OnInit if you override OnInit, not if you
register an event handler.

-- bruce (sqlwork.com)

Howdy Arne,

Infinite loop is caused by calling OnInit from the event handler (C#):

protected virtual void OnInit(EventArgs e)
{
  // this raises the vent you're handling through Page_Init
  if (Init != null)
      Init(this, e);
}

which is (simplifying) equivalent to:

protected virtual void OnInit(EventArgs e)
{
  if (Init != null)
  {
     // equivalent to replacing Init with your event handler
     OnInit(e);
  }
}

As you can see, OnInit calls itself causing infinite loop and stack overflow.

You should change it to:
Public Class MyPage
   Inherits System.Web.UI.Page

    Protected Overrides Sub OnInit(ByVal e As System.EventArgs)
       
        MyBase.OnInit(e)
        ViewStateUserKey = Session.SessionID
       
    End Sub

End Class

There's one more thing: could you please explain why you're setting a view
state property on every postback?

Regards