On rare occasion, you may encounter issues sending or receiving messages, photos or videos, or be unable to connect to WhatsApp. This is usually caused by a problem with your phone's Internet connection, or a problem with your wireless carrier or Internet service provider.
Most connection issues can be resolved by doing the following:
If you use an unlocked iPhone or a pre-paid SIM card, then you may need to adjust your phone's APN settings for your SIM card. Please contact your wireless carrier for details and instructions about changing the APN settings for your SIM card.
Some Wi-Fi networks require that you log in before being able to connect to the Internet. These "captive Wi-Fi" networks are common at airports and hotels. If you are having trouble connecting to WhatsApp while on a Wi-Fi network that you do not normally connect to, please try opening a web page in the Safari web browser to make sure that you are properly logged in and connected to the Internet.
If you are on a campus or corporate Wi-Fi that has firewall restrictions in place, then you should contact your network administrator for help with accessing WhatsApp on your Wi-Fi network. WhatsApp is not designed to be used with proxy or VPN services, so we cannot provide support for those configurations.
WhatsApp Support Team