XML : Xml-Serialization is not working

my XML-Serialization is not working.

The following code throws an exception:

  XmlSerializer x = new XmlSerializer(typeof(GeneralSettings));    

I guess something is wrong with my GeneralSettings class? I can't figure out what the problem is exactly.

Class which shall be serialized:

  [Serializable()]  class GeneralSettings  {      // ---------------------------------------------------------------//      #region Properties for settings      // ---------------------------------------------------------------//      public string ActiveLanguage { get; set; }        public string ActiveLeague { get; set; }        // ---------------------------------------------------------------//