How to Fix the “Connection Problem or Invalid MMI Code” Error on Android?


Android smartphones are known for their versatility and functionality. However, like any other electronic device, they can encounter errors and issues from time to time. One common error that Android users may come across is the “Connection Problem or Invalid MMI Code” error.

Understanding the Error

The “Connection Problem or Invalid MMI Code” error typically occurs when dialing certain codes on your Android device using the MMI (Man-Machine Interface) protocol. These codes are often used to access specific services or settings provided by your mobile network operator.

When you encounter this error, it means that the code you entered is not recognized or supported by your network operator, or there may be an issue with your device’s connection to the network.

Potential Causes of the Error

There can be several reasons why you might encounter the “Connection Problem or Invalid MMI Code” error on your Android device:

  1. Incorrect or mistyped code: Ensure that you have entered the code correctly without any typos.
  2. Network compatibility: Some codes may not be supported by certain network operators.
  3. Network connectivity issues: If you have a weak signal or unstable network connection, it can prevent the code from being executed properly.
  4. Software or firmware glitches: Occasionally, software or firmware bugs can cause issues with code execution.

Methods to Fix the Error

1. Check and Re-enter the Code

Double-check the code you are trying to dial and ensure that it is correct. Even a small typo can result in the error. If you are unsure about the code, contact your network operator for assistance.

2. Use Alternate Codes

If the code you are trying to dial is not working, try using alternate codes that serve the same purpose. Your network operator may have different codes for specific services or settings.

3. Restart Your Device

Restarting your Android device can often resolve temporary glitches or connectivity issues. Simply power off your device, wait for a few seconds, and then power it back on.

4. Check Network Signal and Connectivity

Ensure that you have a stable network signal and a reliable internet connection. Move to an area with better network coverage or try switching to a different network mode (e.g., from 4G to 3G) to see if that resolves the issue.

5. Clear Dialer App Cache and Data

Clearing the cache and data of your dialer app can sometimes help resolve the error. To do this, go to Settings > Apps > [Your Dialer App] > Storage > Clear Cache/Clear Data. Please note that clearing data will remove your call history, so make sure to back it up if necessary.

6. Update Your Device Software

Keeping your Android device’s software up to date can help fix various bugs and issues. Check for any available system updates by going to Settings > System > System Updates and install them if available.

7. Contact Your Network Operator

If none of the above methods work, it is recommended to reach out to your network operator’s customer support. They can provide specific guidance and assistance based on your network provider and the error you are experiencing.


The “Connection Problem or Invalid MMI Code” error on Android can be frustrating, but it is usually solvable with a few simple steps. By checking the code, ensuring network connectivity, and trying alternate methods, you can resolve this error and continue using your Android device without any issues.

Remember, if the error persists, don’t hesitate to contact your network operator for further assistance.

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