Sony xperia5 cannot send a message.

Update the software or change the mobile phone card.

See if there is a network, and check the network status of the mobile phone. Is the SIM inserted incorrectly or the card slot is in poor contact? Then try to update it and see if it can be sent out. You can change your mobile phone to see if you can send and receive text messages. You can send and receive text messages. I suggest you re-insert the card into your mobile phone and send a text message to see if you can receive it. If not, I suggest you check whether there is something wrong with your sim card, check whether the number in the SMS center is set correctly, and take your mobile phone card to the local business hall for testing or replacement.

The SMS center number is set incorrectly. Find the SMS center number in SMS settings. I don't know how to set the problem of online tutorial operator setting. If you set the correct SMS center number, you can't send it out, or you can send it before, but suddenly you can't send it out. It is suggested to call the operator directly and ask them to set it up. Call the operator and you'll know the reason. In addition, sending advertisements to others will temporarily stop the SMS function and can be solved manually. You can receive short messages, eliminate signal problems, and ask people in the same area to confirm before updating and changing cards.