Individual — my data connection not working

Address:

600017

Sir i have purchased lenovo a 6000 2 years before. But recently i have face the problem in mobile data connectivity. When i should start the mobile data unfortunately, process com. Android. Phone has stopped. I[censored] press the ok button another message is displayed in front o[censored] error in set data subscription clean up any existing data connection and try again.
Please guide me