Oppo mobile phone nfc recharges the bus card, which always shows that the system is temporarily upgraded, and the administrator is dealing with it urgently. Just a moment, please?
This prompt may indicate that the system is being upgraded, please try again later. At the same time, you'd better check whether your balance has been recharged. If the balance is used, there is no need to operate again. If the balance is not fully charged, you can wait for more than half an hour before starting the operation, you can also shut down and restart it, or go to a place with good network coverage to operate.