I don't know what is wrong with whatsapp...when someone sends me any message, it doesn't show any notification, and when I open the app I can see that there are many important messages which were unseen and received long ago...this is a really really big problem..most of the people rely on whatsapp to transfer messages and documents. But I'm really disappointed to see such a bad service from such a famous app from popular developers!! Now, even I can't move to another messaging platform...