1, consult the phone bill balance of the mobile phone card to see if there is any arrears;
2. Correct the information center number. First, check whether the information center number of "SMS-SMS Settings-Information Center Number Settings" in the mobile phone is correct (compare it with similar local cards or consult the operator to confirm the information center number);
3. Compare and observe the changes of SIM card and different time periods;
4. Try to restore the factory settings of the backup data (Settings-System "More"-Restore the factory settings, please do not check "Clear completely");
If the above methods fail to solve your problem, please take the purchase invoice, warranty card and mobile phone to the nearest OPPO customer service center for testing and handling.