Hello'
- Uninstall the current Whatsapp version: Go to Settings> APPS> Downloaded> Touch 'Whatsapp'> Touch uninstall and then go to google playstore to download it again.
- Make sure your Date and Time is correct.
- Or you follow the instructions on this link http://www.satechhelp.co.za/1611/Install-Whatspp-Messenger-Android-Without-Adding-Email
Reply below for further assistance.