Changed it to:

<%@ Control Language="vb" AutoEventWireup="false" %>

The code-behind file is as follows:

Imports System

Imports DotNetNuke.Modules.Blog.Business

Namespace DotNetNuke.Modules.Blog

Public MustInherit Class GLSEmail

Inherits BlogModuleBase

#Region "Event Handlers"

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub

#End Region

#Region " Web Form Designer Generated Code "

'This call is required by the Web Form Designer.

<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

End Sub

'NOTE: The following placeholder declaration is required by the Web Form Designer.

'Do not delete or move it.

Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init

'CODEGEN: This method call is required by the Web Form Designer

'Do not modify it using the code editor.

InitializeComponent()

Me.ModuleConfiguration.SupportedFeatures = 0

End Sub

#End Region

End Class

End Namespace

Not it got the following error messages:

Error: Test_UserControl is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Unable to cast object of type 'ASP.desktopmodules_blog_TestUserControl_ascx' to type 'DotNetNuke.Entities.Modules.PortalModuleBase'. ---> System.InvalidCastException: Unable to cast object of type 'ASP.desktopmodules_blog_TestUserControl_ascx' to type 'DotNetNuke.Entities.Modules.PortalModuleBase'. at DotNetNuke.UI.Skins.Skin.InjectModule(Control objPane, ModuleInfo objModule, PortalSettings PortalSettings) in C:\DotNetNuke\Library\Components\Skins\Skin.vb:line 456 --- End of inner exception stack trace ---