I can't finish Blazing Retribution (bug)

There is a bug with the quest blazing retribution (near Llevigar) that makes it impossible to finish.

In order to progress the quest, the player needs to check two camps for the weapon, and then return to the detective. If the player speaks with the detective before that, though, he says they should follow the orc into the lake (which didnt happen yet, the orc only appears after the player checked the two camps). If the player heads to the hidden orc base in the lake before checking out the camps, as I did, they can enter it, and kill Greggr, the orc leader.

I killed Greggr and got the axe, but when I returned, the detective still told me to go towards the lake.

I then realised I had to check out the camps first, and did the quest steps afterwards again. When I got to the base, however, I was blocked by an alpha wall right before the boss fight with Greggr. I am unable to progress from here, and the detective still tells me to go towards the lake.

 

Try the usual relogging and /class, if they don't work, submit a bug report.