This means the mmi code. Correct incorrect MMI code if there are connection problems

The error “Connection problems or invalid MMI code” (or its variation “Invalid MMI code”) can occur in completely different situations. But most often, it appears when sending a USSD request. For example, the reason may be an error in the request or a problem with the SIM card. In this article we will look at all the options for solving this problem.

Error in USSD request

This option needs to be checked first. Even if you have previously used this request code, go to the official website of your operator and make sure that the service you want to use is active. For example, it could have been moved to the archived list or the combination simply changed.

Also, make sure that you yourself have not made a mistake in the set. If necessary, consult your operator's contact center.

This error often appears when sending a request from a place with poor 3G or 4G network coverage. In this case, you should try to force the phone to switch to 2G mode. This is usually done in the “Settings” -> “More” -> “Mobile networks” -> “Network type” menu:

Also, it would be a good idea to restart your phone. If after the steps described above the error does not disappear, you probably have a problem with the SIM card.

SIM card problem

Sometimes, especially with old SIM cards, there are problems. The only solution is to replace the SIM card. Fortunately, this can be done in 5 minutes in almost any office of your operator, completely free of charge.

If you have any questions, write in the comments or new questions, we are always happy to help you!

Owners of Android smartphones (most often Samsung, but I think this is due to their greater prevalence) may encounter the error “Connection problem or invalid MMI code in the English version and “Invalid MMI code” in older Androids) when performing any action: checking the balance, remaining Internet, telecom operator tariff, i.e. usually when sending a USSD request.

This manual contains ways to fix the error Invalid or incorrect MMI code, one of which, I think, will be suitable for your case and will solve the problem. The error itself is not tied to specific phone models or operators: this kind of connection problem can occur when using Beeline, Megafon, MTS and other operators.

Note: You don’t need all the methods described below if you just accidentally typed something on the phone’s keyboard and pressed call, after which this error appeared. This happens. It is also possible that the USSD request you used is not supported by the operator (check with the official communication of the operator if you are not sure that you are entering it correctly).

The easiest way to fix the "Invalid MMI code" error

If the error occurred for the first time, that is, you have not encountered it on the same phone before, most likely this is a random connection problem. The simplest option here would be to do the following:

1. Go to settings (at the top, in the notification area)
2. Turn on airplane mode there. Wait about five seconds.

3. Turn off airplane mode.

After this, try again the action that caused the error.

If after these steps the “invalid MMI code” error does not disappear, try also turning off the phone completely (holding the power button and confirming shutdown), and then turning it on again, and then check the result.

Fix for unstable 3G or LTE (4G) network

In some cases, the cause of the problem may be poor signal reception; the main symptom may be that the phone is constantly changing networks - 3G, LTE, WCDMA, EDGE (i.e. you see different indicators above the signal strength icon at different times).

In this case, try selecting a specific type of network in the mobile network settings. The necessary parameters are in: Settings - « More" In chapter " Wireless network» - « Mobile networks» - « Network type».

If you have a phone with LTE, but 4G coverage in the region is poor, install 3G (WCDMA). If this option is still bad, try 2G.

SIM card problem

Another option, unfortunately, is also common and the most time-consuming in terms of time required to correct the “invalid MMI code” error - problems with the SIM card. If it is old enough, or has been removed and inserted recently, this may be your case.

What to do? Arm yourself with your passport and go to the nearest office of your telecom operator: the SIM card is changed free of charge and quickly.

By the way, in this context, it is still possible to assume a problem with the contacts on the SIM card or on the smartphone itself, although it is unlikely. But trying to simply remove the SIM card, wipe the contacts and reinsert it into the phone won’t hurt either, since you’ll most likely have to go change it anyway.

Additional options

All of the following methods have not been personally tested, but are simply encountered in discussions of the invalid MMI code error in relation to Samsung phones. I don’t know how well they can work (and it’s hard to tell from reviews), but I’ll quote them here:

• Try executing the query by adding a comma at the end, i.e. For example *100#, (a comma is placed by holding down the asterisk button).
• If you have installed any apps recently, try uninstalling them to see if they are causing the problem. You can also check this by booting the phone into safe mode (if everything works in it, then apparently the problem is in the applications, they write that the problem can be caused by FX Camera). How to enter safe mode on Samsung, watch the video below.

Sometimes users encounter various kinds of problems that arise when using smartphones based on the Android operating system. Today we will look at the “Connection problems or incorrect MMI code” error. It can occur when trying to make a call, send an SMS message, or even when requesting a USSD command.

MMI or Man-Machine Interface is the code used when generating USSD requests, but occasionally a failure occurs, which leads to the error that we are discussing in this article.

The error itself looks something like this:

The error can also be displayed in English: Connection problem or invalid MMI. The essence of this, however, does not change.

Now let's talk about solutions that will hopefully help you deal with the problem.

Reboot your device

The very first and simplest thing to do in case of such problems is to restart your smartphone. For what? It happens that there is some glitch in the software that leads to an error. And a reboot in many cases allows you to cope with this (and not only) problem.

Turn on airplane mode

An option that sometimes helps you avoid rebooting your smartphone is to turn on and then turn off airplane mode (sometimes called “Airplane mode”). As you know, in this mode, any data transmission is suspended, and after shutdown, it is turned on again. In this simple way you can try to get rid of the error.

Disable the "Add country code" feature

A solution that has helped a huge number of users: the country code is automatically added to the number, which in turn can lead to the described error. We will show an example of disabling functionality based on a Xiaomi smartphone.

Open “Settings”.

Tap on the section with system applications. Sometimes system applications can be found in the main “Applications” section, for which, as a rule, you need to click on the menu button somewhere at the top of the screen, and then select “Show system applications” from the menu that appears. In our example, this section is placed separately.

Find the “Phone” or “Calls” application and tap on it.

Click "Contact Locations".

Move the "Add Country Code" switch to the "Off" position by simply clicking on it.

After that, try making a call or sending a USSD request.

Change network type

Go to settings, select the “SIM cards and mobile networks” section.

Click Preferred Network Type.

Change the network type.

Usually this is 3G or 4G, but not lower, although you can try, for example, turning on 2G, and then 4G again.

Select operator network

Go back a step and select “Mobile networks”.

Make sure your current network is automatically selected, for example:

If not, then change it, fortunately this can be done through the settings.

Add a character to the number or USSD request

Users write that sometimes a non-standard option helps - adding a symbol to the phone number or USSD code. This could be, for example, a plus sign:

Remove and reinsert the SIM card tray

Another option that may help is to remove the SIM card tray: remove it and put it back in.

Make sure the SIM card is working

To do this, use another phone or smartphone. If an error occurs in this case, the problem is most likely with the SIM card; it needs to be replaced. If everything is fine, the problem may be with your phone. Alternatively, you can reset all data.

Today we will talk about a fairly well-known error that users of smartphones based on the Android operating system may encounter. When sending USSD requests, the message “Connection problems or incorrect MMI code” may appear on the smartphone screen. The message may also look like “Connection problem or invalid MMI code” or even in English - Connection problem or invalid MMI code.

This is what the error looks like on the device screen:

In English:

The question arises - what is MMI? MMI or Man-Machine Interface is a special code that is used to generate USSD requests, which ensures interaction between the subscriber and the operator’s service applications. Sometimes there is a crash that results in the above error. What to do? There are several possible solutions, we will tell you about them in more detail.

Send the USSD request again

Let's say that you decided to find out your account balance by sending a request *100#, as a result of which you received an error, but you do not observe any problems with communication. Try sending the USSD request again, and after a while, if that doesn’t help, try again. This may be a problem on the carrier's side.

Turn airplane mode on and off

Airplane mode, as you probably know, allows you to turn off all communications of the device. Turn on airplane mode for just a few seconds, then turn it off again so that your smartphone finds the network.

After that, send a USSD request. Most likely everything will work.

Reboot your smartphone

In general, turning on and off airplane mode should be enough to solve communication problems. However, perhaps the problem is in the smartphone software - say, there was some kind of glitch. In order to return the device to its previous form, simply reboot it. Or turn it off and on again - whichever is more convenient for you.

After turning on, check the device for errors.

Change network type

Try changing the network type. Let's say you are using a 4G network (LTE). You need to try changing the network type to 3G or even 2G - for a while, then you can return everything to its original state.

Find the "Mobile networks" section in the menu. Here, click on Network Mode.

Select a different connection type.

After that, send a USSD request. If the error disappears, try returning the network type you had set to.

Make sure the operator network is selected

This may be caused by some kind of glitch. You need to select your carrier's coverage. To do this, go to the same “Mobile networks” section and select “Network operators”.

Wait for it to download and select your operator's network.

The procedure may help, especially if you are roaming.

Boot in Safe Mode

There is a small chance that the error is related to the operation of an application. How can you make sure of this? Yes, it’s very simple - just enable safe mode.

In this mode, Android launches only system applications, so you can immediately understand whether the problem is with the application or not.

How to enter safe mode, .

Try adding a character to the USSD request

Some users claim that adding a character to the USSD request can help. For example, a comma.

The USSD request works, oddly enough.

Problems with the SIM card

An error also occurs if there are problems with the SIM card. For example, it is very old and it is time to replace it, or you cut it incorrectly. In such cases, USSD requests will not work at all, you need to replace the SIM card.

If, when you try to make a call, send an SMS or make a request for account balance, a message about a connection problem and an invalid MMI is displayed on the phone screen, then you should do simple manipulations to restore the connection. There is nothing complicated about them and even an inexperienced user can perform them.

The MMI (Man-Machine Interface) code is used to generate a USSD request from the keyboard of a mobile device. It starts with an asterisk and ends with a hash. When performing more complex queries within code, an asterisk is used to separate parameters.
We usually use such combinations when requesting information about balance, expiration date, when replenishing an account, etc.
Sometimes, when performing such a request, an error is displayed on the screen: “Connection problem or invalid MMI code.”
Below are some ways to resolve this error:

1. Problem with the SIM card

Like all electronic products, the SIM card is subject to physical wear and tear and may not function correctly. To correct the connection error, you must contact the service center to replace the card. However, the phone number will remain the same. It is recommended to replace the SIM card every 2 years.

2. Insufficient coverage or unstable 3G operation
Mobile operators are constantly improving their coverage capabilities and using third-generation 3G communications, but it does not always work as expected.
Modern telephones are also prone to modernization. For this reason, by default they use the ability to automatically connect to GSM/WCDMA. But with 3G connectivity interruptions, this network is not always stable.
To eliminate the error when there is insufficient coverage, you need to set the GSM network as follows:
- go to the phone settings;
- then go to the “Network” menu and select “Mobile networks”;
- in the “Network mode” setting, change the network mode to “GSM only”;
- reboot the phone.
This mode does not have to be changed permanently. After a while, try turning on the previous network mode again.
3. Some applications work

Some externally downloaded applications may cause an error with connection problems or an incorrect MMI code. To confirm or refute this suspicion, boot your device in safe mode and try to make a request to the operator. If it goes well, it means that some application installed on the phone is to blame and will need to be removed.

4. Problems with device settings
Incorrect device settings or malfunctions may cause problems with the MMI connection.

Try rebooting the device, and if the problem persists, try performing a full data reset.
Go to “Settings” - “Backup and reset” - “Reset to factory settings”. Please note - all data on the device will be lost!
5. Temporary problems with the mobile operator
In this case, all you have to do is wait. You can call the operator and find out how long the error with MMI will persist.

1 person liked the post