Wondering if anyone can help me with this problem? I have looked all over the internet and have found similar situations and tried their Solutions but nothing has worked. I have a Sprint Galaxy S7 phone I bought off of Craigslist. It is a tri-band unlocked. I am on Straight Talk service. Everything works great accept when I get a voicemail it will not send a notification to my phone to let me know I have it. Let me be clear though everything works perfectly with the voicemail and the phone except this one annoying thing. I have tried resetting my APN numbers. Entering numerical code into the keypad. And I tried using third-party applications like Google Voice and other ones that actually handle your service for you. None of them seem to work as a error during setup except Google Voice. They kept telling me I had an MMI error. It says call forwarding connection problem or invalid MMI code. Conditionally. For all basic services. Google Voice installed fine but I think I need a separate phone number that I have to give out to people to use then it forwards it to my phone. I really don't know much how this works but I really don't want to have to tell everyone that already has my number I have a new number so my voicemail works. Not really convenient if I'm understanding how Google Voice works. Wondering if anyone else has ran into this problem and has any solutions for me to try. Any help would be greatly appreciated as I don't like missing voice mails.