After updatinfg to windows phone 8.1, whatsap works only through wi-fi. It cannot work through mobile data connection. How can I make it to work through mobile data?
I can think of only two solutions
1) Please remove the whatsapp app and reinstall it.
2) Remove the data limit in data sense app then try it out
If even restoring your phone doesn't work out its because your network operator/provider must have blocked the whatsapp data (It is because they want you to spend your hard earned money on the outdated SMS)