Call of Duty Vanguard might be doing a few things differently, but one thing Sledgehammer Games has opted to keep the same is the Camo Challenge system - more or less. If you want to unlock Gold Camo on a weapon - something you'd need to get on all the weapons in the game to unlock Atomic Camo - you're going to need to tackle all the Camo Challenges available.
If you want Gold on the Automaton, you're going to need to complete a Camo Challenge that wants you to use the Assassin Proficiency on this Assault Rifle. There's only one problem with that... Here's what we know.
MISSING - Can't complete this Camo Challenge?
One Automaton Camo Challenge that's causing everyone stress is one that involves the Assassin Proficiency. For one of the Camo Challenges available, you're going to need to get "ADS kills with the Anastasia Sniper Barrel, Embrepp Broadsword Stock, and Assassin Proficiency equipped".
The only issue here is the issue that the Automaton doesn't look like it has an Assassin Proficiency. In fact, this isn't a Proficiency for any of the weapons in Vanguard - at the moment.
That's unusual, right? The Automaton has Proficiency options like Sleight of Hand and Vitals, but Assassin is nowhere to be seen for this gun or any other. This means you can't earn progress towards the Camo Challenge that needs the Assassin Proficiency and ultimately means you cannot unlock Diamond Camo for the Assault Rifles in Vanguard.
As you can see below, a lot of people are having the same issue...
At the moment, Sledgehammer Games is yet to comment on whether the Camo Challenge will be changed or the Assassin Proficiency will be added to the Automaton. Season One is due to start on December 2nd, but we should see an update addressing this error before then.
It could just be the case that this Proficiency option was pushed back and delayed until Season One's content drop - but there's currently no way to fix this issue.