Why is my phone giving error : Connection Problem and Invalid MMI
So my Galaxy Grand 2 was working fine , until yesterday when i was to recharge my balance i have to dial a certainn code like *123*3456# but upon dialing it at first came: USSD code running then and then the message of Connection problem and invalid mmi.
I googled the problem, and tried following solutions
1. Rebooting the phone several times
2. Going into safe mode
3. airplane mode
4. taking sim out and inserting it again
5. trying , and + with the *123*3456#
6. registering to the network by going to Settings>More Network>Mobile networks
So my Galaxy Grand 2 was working fine , until yesterday when i was to recharge my balance i have to dial a certainn code like *123*3456# but upon dialing it at first came: USSD code running then and then the message of Connection problem and invalid mmi.
I googled the problem, and tried following solutions
1. Rebooting the phone several times
2. Going into safe mode
3. airplane mode
4. taking sim out and inserting it again
5. trying , and + with the *123*3456#
6. registering to the network by going to Settings>More Network>Mobile networks
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