Didn't Learn Ability After Level Up

Date & Time: 27102017
Frequency: Constantly
World name: Odin
Character name: Hayastrife Reiya
Class/Level: Dark Knight Level 47

Steps:
1. I am level 47 with my Dark Knight class. So I should have the Ability Dark Arts, you learn this at level 45.
2. When I click to use the Dark Arts ability I can the message "Action not yet learned"
3. I am over the level needed to have this ability so how come I don't have it?

Thanks, I really would like to have this ability as it's a fundamental ability for a Dark Knights rotation.

Kind Regards,
*Add more steps if necessary

Check to see if its not from your Dark Knight class quest you get every 5 levels.

Oh damn... I totally forgot about Class Quests! You're right it's there! I feel like a total idiot!!

Thanks for the quick reply (^,^)/

:) was just a quick guess. I am glad I was right haha.