Hi guys I always got this error from my site and it keeps bugging me.I've been trying to figure out the cause of this error but I can't really figure it out.

Here's the stacktrace:

at BasePage.Page_PreInit(Object sender, EventArgs e) at System.EventHandler.Invoke(Object sender, EventArgs e) at System.Web.UI.Page.OnPreInit(EventArgs e) at System.Web.UI.Page.PerformPreInit() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

And on my basepage I only got this code:

Imports Microsoft.VisualBasic

Public Class BasePage
    Inherits System.Web.UI.Page

    Private Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit
        Page.Theme = "Something"
        If (Request.UserAgent.IndexOf("AppleWebKit") > 0) Then
            Request.Browser.Adapters.Clear()
        End If
    End Sub


    Private Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
        If Me.Title = "Untitled Page" Then
            Throw New Exception("Page title cannot be ""Untitled Page"".")
        End If
    End Sub

End Class

According to the stacktrace this always happens on my basepage preinit event.What do you think is the problem here guys?