1) Turn of Facebook Chat. (訊息中心 -> 設定 -> 使用 Facebook 即時聊天室 -> 關閉) 2) Set Chat status to Offline. (訊息中心 -> 狀態 -> 離線) 3) Go to Battery Saver option in settings. (設定 -> 省電模式) 4) Turn on Battery saver. (打開省電模式) 5) Go to Advanced Settings inside Battery Saver. (進入省電模式中的「進階」設定) 6) Tap on each of the three options there from bottom to top one after another. (從下而上按每一個選項) 7) Come back and turn off the Battery Saver. (回到前一頁,關掉省電模式) 8) Go back to messaging and turn on Facebook Chat. (回到訊息中心,打開「使用 Facebook 即時聊天室」) 9) Now set chat status to available. It should get connected. (訊息中心 -> 狀態 -> 線上)