This has happened to me many times. When i stay in arena after fight (inthe fight area) I get pulled into a battle with no one and after the count down it says that there are not enough players to start the fight. I was wondering if this has happened to other people to.
It's a bug that brings back the old arena. when ever you get near the circle you go into combat. dont know how it works, but it is pretty cool and there have been posts(spelling i think) about bringing that kind of arena back