Hello, friends of the Battlefield community!
Is someone having this problem?
I have been very active in evolving the Mare’s Leg weapon, and when I reached 140 and again with 190 eliminations, instead of getting the four items, only three were released, with the following message:
“There was an error retrieving your items, please try again or contact customer service.”
I tried again, and I got in touch with EA customer service, but they could not resolve it.
I was informed that this is a bug, and that only a developer can correct the problem.
Are other players going through this?
Is it happening with other weapons, or only with Mare’s Leg?
I want to complete the 500 eliminations with her, but it’s not easy.
My intention was to have collaborated, hoping that someone would solve this problem.
Thanks, and I wish we could enjoy the BF4 for a long time …!
This happened to me but don’t worry, you will unlock all Mare’s Leg 's attachments once you reach 500 kills
Thanks for the answer, dear friend Sulabee007, as it increases my motivation to reach the 500 kills.
You’re welcome 
BTW i am trying to get 500 kills with every weapon in the game
Nice! 141 weapon masteries. Highest i’ve seen before you was 134
the game is bugged and you will be super lucky if you get all the attachments. i have over 3300 kills with it and am still missing a couple attachments.
Didnt they remove a couple of the attachments? So you cant actually get them any more, but they are still there as items to unlock (even though you cant).
I am aware that didnt really make sense.
no attachments were removed but when you get battlepacks, there will be a “missing item” slot that comes up. i’m missing a sight, barrel attachment, and laser attachment.
I seem to remember something about the devs removing certain planned attachments before the gun was available, but not making all the other required adjustments to the game. So it seems like you are missing items, but those items are not actually available.
There is a high chance i may have got that wrong though.