Can't turn in quest for Sacellum

[Tradwarden]

Finished a Sacellum Dungeons run succesfully killing all bosses. I was able to turn in every one of the quests except for "Sacellum Slaughter: None Forgotten".

When I select a reward and press "Complete", the window closes and nothing else happens. I tried not selecting a reward, but it simply says I must select a reward. I tried reloading the UI, closing the client and reopening it, and nothing worked.

What I think caused it: When I tried to turn this quest in, my inventory was full, and it must have attempted to finish it, but couldn't give me my rewards, and it broke. Now I can't get my keeper set.

[Kaelang]

This sounds like one for the Bugtracker. Please upload screenshots.