RSS error, "title cannot be null"

title can not be null.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Exception:

Source Error: WriteElement

Source File:

Stack Trace:
at Mako.Web.DesktopModules.Calendar.RssWriter.WriteElement(String localName, String input, Boolean required)
at Mako.Web.DesktopModules.Calendar.RssWriter.writeChannel(RssChannel channel)
at Mako.Web.DesktopModules.Calendar.RssFeed.Write(RssWriter writer)
at Mako.Web.DesktopModules.Calendar.Calendar_Feed.Page_Load(Object sender, EventArgs e)
at System.EventHandler.Invoke(Object sender, EventArgs e)
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Control.AddedControl(Control control, Int32 index)
at System.Web.UI.Control.EnsureChildControls()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Control.PreRenderRecursiveInternal()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)