I have won a game on every skirmish map and still the achievment hasn’t unlocked. Yet i have the halo historian achievement, which after looking it up, says you must complete a game on each skirmish map to unlock a part of the timeline. Advice? 
I have won a game on every skirmish map and still the achievment hasn’t unlocked. Yet i have the halo historian achievement, which after looking it up, says you must complete a game on each skirmish map to unlock a part of the timeline. Advice?