Huawei Glory Play 7X SMS cannot be sent. How to solve it?

Huawei's mobile phone can't send short messages. The possible reasons are as follows: 1. Try to make a phone call to rule out whether it is caused by the arrears of mobile phones. 2. Check whether all the short messages are not received. If individual or partial numbers cannot be received, please check whether the information interception function (such as SMS blacklist) is set. 3. If the prompt shows that the memory is full, please optimize the memory of the mobile phone (for example, delete some short messages). 4. If it doesn't work, please turn off the phone, take out the SIM card and try to insert it again. 5. Update mobile phone system version: Settings-(about mobile phone/system update)-Manual download update/automatic download update (software update/system update-update). Note: Please back up the data in the device before upgrading. 6. If it is the latest version, please back up the data in the mobile phone and try to restore the factory settings.