How to fix a connection issue or invalid MMI code on an Android device

Sometimes a message appears saying “Connection problem or invalid MMI code” and it can be frustrating for Android users. When the invalid MMI code message appears, it usually means that you cannot make calls or text messages until the problem is resolved. This can happen for many reasons.

Fortunately, there are several ways to potentially fix the Android “Connection problem or invalid MMI code” error. Try the following options below. If one process fails to resolve the problem, move on to the next.

What is an MMI code?

Any SIM-compatible device has a large number of codes and numbers, so it can be difficult to identify the purpose of each one. An MMI code (human machine interface code) begins with an asterisk

or pound sign (#) that allows users to enable or disable various star code features (*#06# to reveal IMEI, for example).There are several reasons why the “Connection problem or invalid MMI code

An error message appears on your phone. The main reason is a problem with the operator provider or problems with SIM authentication on the smartphone. The error is quite common on dual-SIM capable phones, but it occurs on others as well.

Ways to fix MMI code error

There are several methods to fix “Invalid MMI code or connection issue” on an Android device. We will cover them from the simplest method to the most complicated ones.

1. Restart Android device

1. The first way to try to fix an invalid MMI code would be to restart the smartphone. Hold the Power button and the Start button
2. at the same time until the phone turns off and starts vibrating; wait for it to reboot. Alternatively, press and hold the button Power button until the shutdown options menu appears, and then selectResume

.

2. Run your device in safe mode

1. Third-party software may be interfering with your connection and causing an MMI error. Fortunately, it’s easy to dismiss this. Here’s what you should do: Restart your phone in safe mode. You can do this by holding down the power button (button combination) on your Android device. Then, press and hold thePower icon
   
2. . Tap Safe Mode
   
3. from the menu that appears.

Now, use your phone in Safe Mode for a while to see if the MMI error appears.

If your phone doesn’t throw any error codes, third-party software is interfering with your network. You will need to start removing third-party apps. Start with the apps you installed at the time you started seeing the error. When you follow the Settings>Applications

path, scroll down and uninstall any app you think may be the culprit. Then turn off your phone from safe mode and see if the error appears. Continue doing this until the MMI code stops.

3. Use airplane mode

1. Some users have had success using Airplane Mode to resolve their MMI code error issues. Gonna Settings and turn Airplane mode toIn
   
2. . Wait 10 to 30 seconds and then turn Airplane mode toOff

.

Since an MMI code error may occur due to weak signal strength, performing this may reset your connection and fix the error.

4. Reset your network settings

1. Since we know that the MMI error indicates a problem with your device’s cellular connection, the next logical step is to reset your network settings. Perhaps your network settings have not been updated correctly or there is a problem in the system. Performing a network reset will clear any trouble codes and help you start over. Here’s what you should do: Open the Settings on your Android device. Then touchGeneral Administration
   . You can also use the search icon and writes Restart
   
2. to skip step 2. Scroll down and tapRestart
   
3. . Tap RestartNetwork settings
   
4. . Tap Reset settings

to confirm. Your phone will reboot.

When your phone restarts, the error should disappear.

5. Modify the prefix code

Another way to fix the connection issue or invalid MMI code on an Android smartphone would be to add a comma to the end of the prefix code. When a comma is added, it forces the operation to be executed and ignores any errors.

1. Below are two different ways to modify the prefix code.If the prefix code is (*2904*7#), then add a comma at the end, similar to this (*2904*7#,
2. ). You can use the +symbol after *similar to this (*+2904*7#

).

1. 6. Activate radio and turn on IMS via SMS Go to thedial pad
2. .Write(*#*#4636#*#*
3. ) NOTE: It is not necessary to press the send button, it will automatically appear in Service mode.
4. Enter service mode. Select Device Information
5. o Phone information. SelectRun ping test
6. . Click on the Turn off the radio
7. and then the Galaxy will reboot. Selectrestart

.

Frequent questions

Hopefully the MMI error will be gone by now. But, if you still have doubts, keep reading.

Do I need to get a new SIM?

If you have tried all of the above solutions and the error continues, you may need to contact your cell phone provider for more information. They may recommend a new SIM or they may resend OTA (over-the-air activation).

Android MMI code error resolved

In closing, there are a few methods/options you can use to fix the MMI error on your phone, some a little more complicated than others. While most MMI errors occur on dual-SIM phones, they also appear on single-SIM phones due to weak signals or issues with the tower network. If the above solutions do not work for you, please contact your service provider for help.