[161215] ZU680KL_ WW_13.6.15.21

【Version】
WW_13.6.15.21

【Model Name】
ZenFone 3 Ultra (ZU680KL)

【Release Date】
2016/12/29

(It takes about one week for the system to complete the autopush, if you did not receive the updation, please go to 【Setting】->【About】->【System Update】to update manaully)

【Release Note】

1. Fixed Gt VoWiFi drop call after 25mins
2. UpdateFileManager version
3. Security Update