This error message may appear if you or the person you are chatting with recently reinstalled WhatsApp or are using an older version.
Causes
- The sending user has not been connected to the Internet for some time.
- You have reinstalled WhatsApp on another device.
- Problems with WhatsApp multi-device mode.
- WhatsApp beta version bugs.
To resolve this:
- Ask the person you are messaging to open WhatsApp on their telephone.
- Make sure that you are both using the latest version of WhatsApp.