Problem after JELLYBEAN update

[srini1691]

:'(
I have a phone Micromax Canvas A110, I upgraded it to Jellybean today and to my horror I lost all my phone contacts. In addition to it I am unable to use the Whatsapp application. I reinstalled it and launched the app and still it is not processing properly and start the application. I am not even able to take printscreen... Please help

 

[HNNNNNGHHH]

Try doing a hard reset of your device. That tends to fix any errors corresponding with an OS update.