Step 5 of this quest is 2 hails of Brother Dilgen. As is normal for TDS quests with steps involving hailing the same NPC multiple times in a step, there is a minimum time necessary between hails. The first hail on step 5 will give you the clickable item required for steps 6-9, and the second will actually unlock the steps in the task window. If you fail to notice that you have not met the minimum time required between hails and proceed to steps 6-9, the scripts for those steps will run (triggered by mob damaged to 50% and the item clicked) but the step is not marked complete. This leaves the character doing the quest permanently bugged. Going back and hailing the step 5 NPC and redoing steps 6-9 or even dropping the task and starting it entirely from the beginning does not allow steps 6-9 to update. This task has my main totally blocked from any further progress in TDS, as its necessary for access to the first T3 zone.