Why did all the text messages on iphone4 suddenly disappear?

Reasons for SMS disappearing automatically:

1: Software sending similar to "flash message", which is only displayed once and cannot be saved.

2. System version BUG problem.

If there is backup information, it is recommended to restore it.

The recovery operation is:

1. Select a backup tool, such as Baidu Cloud, 360 Network Disk and Wei Yun.

2. Open the network disk tool on the mobile phone and start the backup.

3. After success, open the network disk tool on the new mobile phone, log in the account, and restore the backup to the mobile phone.

4. That's enough.