There is no doubt that smartphone gives us a complete package of entertainment in a small device. But if you cannot make any call or send messages from your phone, then there is no use of it, no matter how much entertainment you get from it. MMI code error is a very common problem that a lot of android users face and this error does not allow them to text or call. Sometimes this error does not let you to recharge your android phone through airtime. The error usually occurs when you try to call someone and it shows you a message like “Invalid MMI code”. This error can be occurred if there is any problem with your carrier provider or because of SIM authentication.
See also- 6 ways to fix connection issue or invalid MMI code
Possible ways to fix MMI code error problem on android device
Here I will discuss some steps to fix the MMI error code issue; you can try them one after another.
Method 1
The invalid MMI code on android device could occur because of a recently installed app. So it is advised to uninstall the app. You can boot your phone into Safe mode and try to make call or type any code of your service provider such as *123#, *141# etc.
Method 2
You need to select your provider manually in this method. For that, go to Settings > Connection > more networks > available networks. The list of all available networks will be shown to you. Select the required one and then you need to reboot your android device.
Method 3
Another way you can try to solve the MMI code error is to adding a comma at the end of the prefix code.
Method 4
This method is very easy but the most effective one. You need to add a plus sign (+) at the starting of the code or comma sign (,) at the end of the code. It helps the android devices to neglect any types of error and perform normal function.
Method 5
You can say this is the simplest way, you need to restart your phone and see if the error is gone. If not, then restart again. Continuing this process 3-5 times can fix the MMI code error issue on android devices.