How to Fix error in application

[Arya J]

My phone is lenovo a6000 and Sim is airtel 4g running on android lollipop. An error in application is shown every 30sec and Sim tool kit is missing. Help me to fix this.

 

[B. Diddy]

Welcome to Android Central! What error in application are you talking about? What exactly does the message say? What does the SIM Toolkit have to do with this? Is the error mention SIM Toolkit?