There are a few possible reasons why your WhatsApp messages might not be sending. First, make sure you have a strong data or Wi-Fi connection. If you’re using cellular data, try turning on LTE data or connecting to a different Wi-Fi network.
Next, check to see if you have any pending updates for WhatsApp. To do this on an iPhone, go to the App Store and click Updates. On Android, open the Google Play Store app and tap Menu > My apps & games. If there’s an update available for WhatsApp, it will appear here.
Another possibility is that your phone number isn’t properly registered with WhatsApp. To fix this, open WhatsApp and go to Settings > Account > Change number. You’ll be prompted to enter your old and new phone numbers. Once you’ve done this, all your WhatsApp contacts will be notified of the change.
If you’re still having trouble, try reinstalling WhatsApp. Sometimes this can fix error or other issues. To do this on iPhone, go to the App Store and tap the icon next to the app’s name. On Android, open the Google Play Store app and tap Menu > My apps & games. From here, you can either uninstall and then re-install the app, or tap Update if there’s a pending update.
Hopefully one of these solutions will help get your WhatsApp messages sending again.