Connection problem or invalid MMI codeSometimes if you dial an USSD code in your Android smartphone, to check talk-time balance, internet balance or validity , you may end up with an error "Connection problem or Invalid MMI code"
What is MMI codeMMI code stands for Man Machine Interaction or Man Machine Interface code. Usually it would be a numeric code starts with * and ends with # that looks like *123# or *123*11# that gets the response with the network server and display the information in users screen.
So, in-order to solve the issue , you have to check following things to solve the issue.
- Ensure that you have signal coverage for your network. If not, get in to a good signal coverage area and dial the ussd code again.
- Ensure that the USSD code that you have dialed is a valid one and applicable for your network provider. You can check this by calling to your customer care executive or by just cross checking with the official website of your networks provider.