When you click on install update it does not automatically stop the buzztv app.....I'm not sure where you would have gotten that idea. Click on install update and awhile, let the unit do its work. If the message keeps returning even after you reboot it means you are doing something to interrupt the installation.
Click on install and put the remote out of your hand..... The app will reboot itself and may return to a blank screen or back to live tv, if the screen is blank hit menu and exit app. Reopen and check which version you have by pressing menu button, version is listed at the bottom.
Not sure which box you have but most boxes have a Factory reset which is usually located in Settings> About Box but there should also be a reset pin hole to reset it back to factory but don't hold my feet to the fire as I don't have a lot of android boxes and the ones I do have are all the same make and model but some with Android, 6.0 others with 7.1 but they all have same 3gb ram 32gb rom, dual antennas 918 processor with 4K HDR 3D support.