Unlocking Hero Battles

How do I do it? My PvE characters all have Hero Battles unlocked, but my PvP characters don't and it keeps telling me that I have to unlock Hero Battles (Outpost) first, so how do I do that?

Yeah. Uh. Did that already. That's why I'm asking here dear. Thanks anyway.

EDIT: Not to mention the fact that my account already meets all prerequitsites listed, which is why I'm asking, and I quote myself here:

I really don't know how I can simplify it anymore for you. I'm sorry.

EDIT: #2. I think I found a way to simplify it for you. Please follow [LINK].