Guild Wars 2

In the Lion Arch Battle with where the new Red, Blue, Green knights. The portals they leave all seem to say that you need a “prime attunement” to enter.
One person said that standing on the coloured fields is the key.. but the conditions they leave lasts for 6mins. Each battle takes up to 40mins and 5mins to travel to each.
So far no one has yet to get a prime attunement.. let alone knows the exact way of getting one.
Though i think it’s ridiculous that we need something that is very hard to get to enter the portals, after all the previous battling we did.

The portals re-appear on the other knights’ locations. Last one we fought a while ago was red and the other two portals were there offer a re-attune after we finished.

http://dulfy.net/2014/03/04/gw2-battle-for-lions-arch-achievement-guide/

Maybe the last point of that guide will make it clearer what to do, there is a screenshot too showing the buff fields.

After killing the knights, there will be 3 coloured circles, red, green and blue. Run through all of them and you will get a white buff and can enter the portal.

Apart from the first run after the patch, yesterday those fields were bugged on overflows (didn’t appear at all), so maybe that was your problem.