"Black Ops 3 Error code ABFG in Xbox One" may appear when Black Ops 3 version is out of date. You may want to check for an update. To check for update, restart the game then let the game load the update in the main load screen.
"Black Ops 3 Error code ABFG in Xbox One" could also be due to the Black Ops 3 or Xbox live server. A server could be down. For Black Ops 3, check here to confirm, while for Xbox live server check here. It could also be caused by your internet service provider (ISP). Check your internet speed here. If speed it below normal, call your internet service provider.