4 Methods to Solve ‘Connection Problem or Invalid MMi Code’ Problem

Did you know that How to Solve ‘Connection Problem or Invalid MMi Code’ Problem. If you stuck in this “Connection Problem or Invalid MMi Code” problem, then we are here to help you with this simple problem.
Fix Connection Problem or Invalid MMi Code —
People used to ask, how to fix USSD codes not working? How to fix connection problem or invalid mmi code? How do I solve "connection error or invalid mmi code" problem? Any way for USSD/MMI Fix? Most of the users facing this error while call forwarding connection problem or invalid mmi code issue on phone. Here we are going to share the top 4 best methods to solve and fix your ‘Connection Problem or Invalid MMi Code’ Problem.

Well, it’s a serious problem which will affect the phones that result in imposing some restrictions while sending and receiving text messages and calls. Though the error is generally seen in the dual SIM mobile phones, it may sometimes also occurs in single SIM phones too.

It basically pop up when you call to someone or check your balance because of the SIM authentication problem or the network service provider issue.

To get rid out of this issue I am sharing you this top 4 effective methods which will solve your ‘Connection Problem or Invalid MMi Code’ Problem.

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4 Methods to Solve ‘Connection Problem or Invalid MMi Code’ Problem

1. Check the Network Settings

For solving this ‘Connection Problem or Invalid MMi Code’ problem, here this is the 1st method to fix this Problem. For that You should check your Network Settings.

• Go to Settings
• Select Network Connection
• Follow Mobile Networks
• Search Network Operators
  (It will search for Network Operators)
• Select your Network

That’s it, Done.

2. Activate the Radio to Turn on SMS over IMS

To Fix the ‘Connection Problem or Invalid MMi Code’ Problem, this method is very simple just by entering into device information mode and Activate Radio to turn on SMS over IMS. So for that,

• Go to Dial Pad
• Dial *#*#4636#*#*
  (No need to press the call button, it will automatically appear the service mode)
• Select the 'Device Information' or 'Phone Information'
• Select ‘Run Ping Test’
• Click on ‘Turn Radio Off’ Button
• Then, click on ‘Turn on SMS over IMS’
• Reboot your phone & Check.

That’s it, Done.

3. Add a Comma(,) or Plus(+) Symbol to your USSD number

It is the very easy and effective method to solve this ‘Connection Problem or Invalid MMi Code’ problem by just adding the comma(,) symbol in the ending of number or add (+) symbol before the number.

3.1 By the Comma(,) Method

• If your prefix USSD code is *12345#
• Add the Comma (,) symbol in the ending
• like ex.: *12345#,

3.2 By the Plus(+) Method

• If your prefix USSD code is *12345#
• Add the Plus (+) symbol in the beginning
• like ex.: +*12345#

That’s it, Done.

4. Restarting Phone

• Just restart your mobile phone and turn your phone ON again.
• Go to network settings.
• Scan for nework update.
• If not working, reboot again.
• You need to reboot your phone atleast 2-3 times to see any progress.

And then finally, your mobile will get the network and start working.


These are the very easy, effective and best method for solving and fixing this ‘Connection Problem or Invalid MMi Code’ Problem.

Hope you will learn and like this post.