"SIM Tool Kit: Error in application" pop-up always shows on Lenovo Vibe K5
Check if both SIMs are activated or not. If not, kindly recharge and activate it. The pop up will not come.

Ex. I got this error due to Airtel SIM and my SIM's incoming outgoing was already stopped. I also got the same error, also tried all things posted on internet and YouTube. I recharged RC 35 and it automatically resolved.