In fletcher's hollow Drustvar there is a seething cache in a small building that it appears i have not looted, but when i click it the mobs spawn and i kill them but after a while it just ends with no conclusion, i have tried multiple times, in diff specs and even in a group. all that happens is there is a flash after killing quite a few mobs then they dissapear but i have no chest to loot as it dissapears as well.
I had the same issue but I did it twice before it stayed open and allowed me to loot.