Text from Unknown: Message Not Found

Hey @MathildaM,

This issue can be caused by a few things.  One of the most common is low or intermittent coverage.  If you are in an area with 0-1 bar of service, there can be a delay in getting your messages.  It may also be a sync issue with iMessage and/or Facetime.  To resolve, you'll want to disable and re-enable both features.

• For iMessage:
  
  • Open Settings
  • Tap Messages
  • Slide the iMessage switch to the Off position. This turns off iMessage on your iPhone
• For FaceTime:
  • Open Settings
  • Select FaceTime
  • Slide the Facetime switch to the Off position. This deregisters your phone number from FaceTime

Turn off you iPhone and then turn it back on.  Once the device has restarted turn iMessage and Facetime back on.

If this doesn't work to resolve, you may want to reset your network settings.  This doesn't delete any pictures or software, it only puts your network settings back to default.  You will need to reconnect your Wi-Fi and Bluetooth connections.

• Settings
• General
• Reset
• Reset Network Settings
• Once you enter your password, the phone will reboot

Thanks

Anthony, AT&T Community Specialist