Repeatedly getting "Error in application" USSD popups after iOS 11 upgrade

[quintessential49]

After upgrading to iOS 11 on my iPhone 7 Plus, I started getting USSD (edit: looks like this is called "flash SMS", not USSD) popups (see below). If I tap "Accept", the popup goes away, but it shows up again very quickly. I'm currently in India, and this is happening on Airtel (an Indian carrier). When I use my roaming AT&T SIM instead, I don't see these popups. Does anyone know how I can fix this problem with my Airtel SIM?

 

[quintessential49]

I was able to solve this problem by getting a new SIM card from Airtel. No changes had to be made on my phone.

 

[kailasht949]

After upgrading to iOS 11 on my iPhone 7 Plus, I started getting USSD (edit: looks like this is called "flash SMS", not USSD) popups (see below). If I tap "Accept", the popup goes away, but it shows up again very quickly. I'm currently in India, and this is happening on Airtel (an Indian carrier). When I use my roaming AT&T SIM instead, I don't see these popups. Does anyone know how I can fix this problem with my Airtel SIM?

I was having the same issue with android phone as well as iPhone. It has nothing to do with iOS 11, But lucky for us I have a solution. The only solution is to get a new airtel sim with the same number, it only took an hour to activate and they did not charge me anything for the new sim. everything is fine now, no frustrating pop ups every 30 seconds. I hope it works for you as well...