Windows Phone. Security and Privacy.
Seeing "Waiting for this message. This may take a while."
At
times, you might see the above message in place of what you were sent
from a contact. Due to end-to-end encryption, you might need to wait for
someone's message to arrive because their phone needs to come online
and properly encrypt the message for you. This can typically occur if
you or the person you're chatting with recently reinstalled WhatsApp.
To speed up this process, you can try asking the person you're messaging to open WhatsApp on their phone.
To speed up this process, you can try asking the person you're messaging to open WhatsApp on their phone.