I have completed all of the challenges, three star and all, and can view all the leaderboards but it never gave me the achievement.

I really don't thing sd/bethesda gives a damn they have your money already.

You were a bit unclear: did you complete the three star challenges solo or co-op? The achievement only is unlocked when you do so solo with no help from other human players.

I seem to have this problem to, I just finished all 3 stars solo but didn't get the achievement. I did it on my second character though, should I have done it on my first?

• Check the leaderboards of the challanges for your rank.
  
• Play the challange where you not in the leaderboards again.-

Have you completed them all with the same character and on your own?

Same here - I've completed two of them, twice each - and still no achievement or weapon unlocks as it states on the attachments when you select them. Example, the silencer, you need to complete a challenge - I've done that one twice. Still nothing.

I did them first on my own (assuming that's the way it had to be) and then the second time with actual people. I'm at a loss, anyone?

Me to! ive completed all 3 star challenges at least 2 times and still no achevement.. glitch? or am i missing somthing?

if you start a new character and do the challenges agian you can get the achevement, atleast it worked for me. i think tower defence glitched for me cause it said ive beaten it and i did several times but i could not look at the leaderboards "close to me".

I think there is an option in the xbox profile that allows you to toggle the notifications, so are the achievements regestering but not getting the blip in-game, or are they not unlocking?

I was able to get the achievement, and I used my third new character because trying to do the 3 star "Be more objective" solo at level 20 is on the verge of being almost impossible with the engineer objective being right infront of the enemies spawn point and all. :banghead:

I also did everything in the one sitting, so I didn't exit the challenge modes untill I completed all 3 level of a challenge on solo before moving to the next one.

I also did them in sequential order too.

So the above might help (???)

alright I got mines, turns out when I last finished the parkour this I finished right on zero and even though it said I finished it, it didnt give me the achievment

They are not showing, nor are they unlocking what they said they would unlock - like weapon attachments.

I think it's a glitch - if it's not, please educate me!

Thanks!