Note: These methods are carefully curated from all over the internet and relative forums. I don’t take any credit of coming up with them. Wonderful people of the internet have helped me in creating this insightful guide. I have also not tried these methods myself as I don’t know how to replicate the invalid MMI code error. However many posts in credible forums report that one of these methods helped.
Method 1 – Disabling AppsSometimes an app is responsible for the pesky behavior of your smartphone. You just need to find out which one is guilty of inducing this annoying error. I would recommend that you delete recently installed apps from your smartphone before following this method. If the problem solves itself, all is good then. But if it doesn’t, you may need to access the device in safe mode. Safe mode on Android is same as on Windows. It basically disables all the apps and only gives you access to the essential ones.
- Turn off your Huawei smartphone by long pressing the power button and selecting turn off.
- Some Huawei phones have the option of rebooting into safe
mode. If it is there when you long press the power button, select it.
Otherwise carry on to the next step.
- Now that your phone is turned off, press the volume down
button. While it is pressed, push the power button down until the phone
- Now you will have entered the safe mode. A small indication will appear on the bottom left side of the screen.
- Now you will do some testing and tinkering to find the guilty app. Enter the same prefix code you were entering before.
- If the code works, then you will confirm that there is an app doing the nasty business on your phone.
- Now reboot your phone and uninstall each and every recently installed apps.
Time: 3-5 Minutes
Method 2 – Adding SymbolsThere is another easier method to encounter the invalid MMI Code error on Huawei phone. All you need to do is add a comma at the end of the prefix code.
- If your prefix code was, shall we say *7667*9#you can simply add a comma at the end. Then it will look like this: *7667*9#,
- Alternatively you can add in the plus symbol right after the asterisks symbol. It will look something like this: *+7667*9#
- By adding in the comma, the prefix will be enforced and the device will try to overlook any errors.
Time: 10 Minutes
Method 3 – Information ModeThis method involves getting into the information mode of your smartphone.
- I believe the code for information/testing mode is ##497613 but I could be wrong. Enter the code into the dialer like you always do.
- A new screen will pop up with lots of information which you can ignore as most of it is of no use to us.
- Navigate to the device information.
- Tap on the Run Ping Test option. A small test will be performed on your device.
- Now clock on Turn off Radio.
- After that simply click on Turn on SMS over IMS. Here IP stands for Internet Protocol, IMS for IP Multimedia Subsystem and SIP for Session Initiation Protocol.
- Now reboot your Huawei smartphone. Hopefully this will fix Invalid MMI code error on Huawei phone.
Methohd 4 – RestartingWell this may sound incredibly stupid but restarting your phone can actually help. This is what we call the “magic method”, there is no solid science behind it but it just might work.
- Basically, go to the network settings.
- Turn off your phone.
- Do this several times again. Preferably at least 3 time.
Time: 5-10 Minutes
Method 5 – Select NetworkThis method will involve selecting the network again. It’s a simple method but might take a while to complete this.
- Go to your smartphone’s settings.
- Find the setting called Network Connection. From there go to Mobile Networks and then Network Operators.
- The phone will start searching for all available networks in
your vicinity. It can take a little while to do that so don’t quit on
- After the list is populated, you will need to select your carrier.
- This usually solves the problem.