There is nothing in the message, but a red exclamation mark is displayed. What happened?

A red exclamation mark indicates that the message was not sent successfully.

Solution (Take vivo X9 mobile phone as an example) Check whether the number of SMS center is correct:

1, standby desktop entry setting

2. Information

3. SMS center number

4. Check whether the number of SMS center is correct.

Precautions:

1. First of all, it may be that the mobile phone really has no signal, or it may be that the mobile phone is in flight mode.

Solution: first check whether the flight mode is on, if it is off, if the cell phone signal at the current location is not good, you can make a call from another location.

2. This problem may also occur if your SIM card is not inserted correctly or has poor contact.

Solution: Pull out and reinsert the SIM card of the mobile phone. Generally, the SIM card needs to be replaced after 3 years of use, otherwise it is easy to get poor contact.

3. If the mobile phone card is in arrears, you can ask people around you to call you to see if the prompt tone has stopped.

Solution: The mobile phone stops due to arrears, and can be used normally after payment.

There is something wrong with the network system of the mobile phone.

Solution: Turn on the phone to restore the network settings and wait for the phone to restart to see if it solves the problem.