Fix “Connection Problem or Invalid MMI Code” error in Android

Some Android devices show a strange error on dialing numbers that start with * (asterisk) and end with # (hash). Such numbers are generally the service numbers or device utility codes, eg. numbers to quickly flash your balance, IMEI code etc.

The following string is reflected in the error: “Connection Problem or Invalid MMI Code

This error won’t let you make use of the number or code you dial on your Android device, and you won’t be able to use any similar numbers on it. See below screenshot of the error message:

Connection Problem or Invalid MMI Code - Android Error

How to fix this error?

I was really fed up of getting this MMI code error before I found a simple solution that I’m sharing with you in this post.

This fix won’t include installing an additional package or app on your Android. When dialing a number, say *123#; just add an extra character , (comma) at the end of the number (i.e. *123#,). Doing so fixed the error at my end, but a few of my buddies are still complaining about this quick fix. Hope this has worked for you too.