I contacted United Airlines in Germany on that issue an thatīs their response in german language:
"Sehr geehrter Herr ....,
Thai scheint zur Zeit technische Probleme zu haben, uns deren Plaetze zur Verfuegung zu stellen. Leider koennen wir Ihnen nicht sagen, wann das System wieder laeuft, allerdings duerfte es nicht allzulange dauern.
Vielen Dank fuer Ihre Geduld.
Beste Gruesse,
Ihr United Airlines Team"
That means:
"Dear Mr....,
Thai seems to have technical problems at the moment to offer us reward space availability. Unfortunately we donīt know when the system will run again, but it should not take to much time.
We thank your for your patience.
Best regards,
Your United Airlines Team"