This video shows that how to fix connection problem or invalid mmi code on android phone.these type of errors are occuring due to the sim card management .brHow to Fix Connection problem or invalid MMI code error occurs in any mobile phone having any Network Providers (SIM). Are you getting the message .brFor instant recharge, i am dialing *120*16 digit pin number from the recharge coupon or voucher#. At this time ussd code starts running and displays .brHow to fix Running USSD code error Connection problem or invalid MMI code in Any phone model like Samsung Galaxy Note 4, Sony xperia, Moto g, .