I got this exception today after downloading and installing on Windows 7. When I tried to open a link from MS Outlook I was getting the following exception and to fix it I changed BrowserList.vb, line 107 And to AndAlso.
System.NullReferenceException was unhandled
Message=Object reference not set to an instance of an object.
at Browser_Chooser.BrowserList.GetBrowserByUrl(String url)