We've found the issue is caused by some iOS version which having login issue and failed to connect.
You are not suggested to upgrade.
The solution is try downgrade the app or remvoe the app and install it again .
最近幾日有收到反饋ios下WhatsApp登陸故障。
經測試發現為部分ios下WhatsApp版本故障，造成登陸故障
解決辦法為，降級到以前舊版本，或刪除，重新安裝一次。
Monday, January 6, 2020
