Quest: The Demons Behind the Wall doesn't proceed

Quest ID: 427256

Quest Name: The Demons Behind the Wall

(Main Quest Chain - The Spirits of Despair)

Zone 33 Moorlands of Farsitan

I wanted to do this quest, but the NPC "Pritschi Akson" always says "already running, participate or wait for end". The necessary mobs aren't spawning and it doenst proceed.

When did you do the Quest Daleshy?
Thanks for your advice rmsagarm, but sadly, it didnt work for me.

At the NPC, I encountered two other guys, who have the same problem. Is it necessary, that ALL ppl are declining the quest to fix it?

But the problem is, there are no quest mobs (marked with an arrow above). Only regular mobs are spawning and no event mobs. I did the quest a few days ago with another character and everything was fine, but since yesterday I cant proceed it with another char.