As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE MASTER WARNING DISPLAYED FOR 5 SECONDS AT FL410. THE WARNING EXTINGUISHED WITHOUT INTERVENTION. AS A PRECAUTION WE RAN APU FIRE CHECKLIST PROCEDURE AND DISCHARGED THE APU FIRE BOTTLE. STATUS LEVEL MESSAGES "BOTTLE LOW APU" AND "APU. REMOVED APU FIRE BOTTLE & INSTALLED A SERVICEABLE BOTTLE IN REF TO MM CH 26-22-01. OPS CKS OK. EFF SOURCE REF IPC 26-22-01-02-060.