B4J Question [ABMaterial] 4.0 problem with stability

Public Sub NavigateToPage(ws As WebSocket, PageId As String, TargetUrl As String) 'ignore
    '----------------------MODIFICATION-------------------------------
    Dim testTargetUrl As String = TargetUrl
    If Not(testTargetUrl.EndsWith(".htm") Or testTargetUrl.EndsWith(".html") Or testTargetUrl.EndsWith("/")) Then
        TargetUrl = TargetUrl & "/"
    End If

    If PageId.Length > 0 Then ABM.RemoveMeFromCache(CachedPages, PageId)
    If ws.Open Then
        ' it doesn't keep navigation history in the browser (the back button exists the application)
        'ws.Eval("window.location.replace(arguments[0])", Array As Object(TargetUrl))
        ' if you need browser history just comment the lines above and uncomment the lines below
        ' it keeps the navigation history in the browser
        ws.Eval("window.location = arguments[0]", Array As Object(TargetUrl))
        ws.Flush
        'ws.Close <----- DELETE
    End If
    '----------------------MODIFICATION-------------------------------
End Sub

If session.IsNew Then
  session.Invalidate
  ABMShared.NavigateTo(.....) ' whitout that code the ws connection will remain open if the client isn't a browser
End If