I have completed all the Spartan Ops missions many times each, all on Legendary or Heroic difficulty yet I have not received the Achievement for completing all the Missions. Any idea why?
Me too.
But I haven’t completed the last episode, solo.
I assumed that was why, even though it doesn’t actually specify that.
Have you completed all the episodes, solo?
There’s a glitch that is causing the problem you are experiencing. I had the same issue, but I resolved it, like many others have by replaying Spartan Ops Episode 1 Chapter 1 solo on easy.
Doesn’t even matter what chapter you play. I simply replayed an episode 5 chapter solo on easy and it popped up.
Hope that works. I’m in the same boat.
It worked, Playing a mission solo on Easy. Thank you very much for the help.