For those of you who cannot see the new "loopy braid" Elin hairstyle in their game and now have bald Elins running around: this is because you have somehow modified your Popori_F_Head.gpk file in the past. The most common reason for this is that at some point, you applied one of the "patches" that replaces the European Elin armors with the standard Korean ones. Also known as "the Elin Decensor".
If you want to fix this, go to your TERA folder and find this path:
...\TERA\Games\GBR_eng\TERA\Client\S1Game\CookedPC\Art_Data\Packages\CH
You will probably have one subfolder called "PC" and one subfolder called "_PC" there.
Now go and copy/paste the Popori_F_Head.gpk from folder PC to _PC, thus overwriting the one in _PC.
Done - the new hairstyle will now render properly in game.
Note that this will not change anything about the Elin armors, your game keeps whatever look you had for them before.

(PS: in some cases, this can cause the very first elin face and the first elin hairstyle to be rendered as 'black' in character creation. Not a problem, though: they will be displayed completely normally in the actual game.)