Hi.
It got stuck for me too just now. The party didnt move on from the first tower and when it came to the part to clear out the beach it didnt show where. I DID just blow up the towers without killing the undead first, which maybe I shouldnt have done. But I just went on and killed all the undead around the three towers and then it went on, so it seems like its working (kinda) now, except for that the borders are not correct. You can be kicked out from the instance and have to start all over again even that you are way inside the barriers.
I dont know if the order has anything to do with this, but I killed the mobs around tower 1 first, then 2 and finally 3.