If you choose the event RSS Feed, then select the entire URL that is prepopulated and CTRL+V a new URL in there, the application crashes with the error being on line 231 of FeedAlertConfig.xaml.cs where it says:

if (CanSave)
{

  FeedCatergory.Text = channelNode["title"].InnerText;

}

channelNode is null at this point.