Guild Wars 2

I can’t do this Quest. In the part of defending the gate appears several risen but suddently they stop appearing and I can do nothing for finishing the quest because there are not mobs to kill.

Character “Serval de Jade”

I hope a solution, its my only character and I want to finish the game with him. I don’t care if the solution is making me miss this chapter (as if I had already done it)