Dark Age Rush or Early Adopter Achievement

Navigate to your library and select "Age of Empires (2013)"

Select "Support".

Select a DLC. (When i did it i selected Rise of the Rajas)

Select "I want to permanently remove this game from my account". Don't worry you will still own this DLC and will be able to get it back as soon as you get the achievement.

Select "Ok, remove the listed games from my account permanently"



You should then get this message.

Now launch Age of Empires and go to any campaign mission (I went to Joan of Arc 1st mission).

Lose the mission by deleting all your units etc.

As soon as you get the defeated message / return to the main menu the achievement should pop.

Repeat step 1, 2 and 3.

Remember to re-select the same DLC.

Select "It's not in my library".

Select "Restore the previously removed package to my account".



You should then get this message.

Celebrate because you finally have this dumb achievement. :D

Also feel free to leave a comment and i will do my best to help.

Also (again) if you need help getting the other achievements here is a good guide that will help.
100% Achievement Guide