I picked the lock, but when I could not loot for the key, I went back in and the leader was there. I defeated him and his goons, but still could not complete it. 

 

I also started having the same issue with the quest with the chest on the same map. 

Description:

When attempting to complete the "Supply and Demand" quest, I was able talk to the quest-giver and receive the quest, but I something has gone wrong, disallowing me to complete it. After fighting the first thugs I encounter, next to the statue, I am unable to loot them and continue the quest. After my first try, I loaded from an autosave just after I had accepted the quest and tried again. I had the same issue once more. Cannot loot the thugs, cannot continue the quest. I went ahead and defeated all other thugs I could find on the map, including the ones in the locked house, but I still can only answer "Not yet" to the quest-giver's inquiry as to whether or not I have taken care of the thugs.

 

Steps to Reproduce the Issue:

From the save file, try to loot the

 

Important Files:

https://www.dropbox.com/s/r2le0d3tnpe4lhg/PoE_Supply_and_Demand_bug_report.zip?dl=0

Description:

When attempting to complete the "Supply and Demand" quest, I was able talk to the quest-giver and receive the quest, but I something has gone wrong, disallowing me to complete it. After fighting the first thugs I encounter, next to the statue, I am unable to loot them and continue the quest. After my first try, I loaded from an autosave just after I had accepted the quest and tried again. I had the same issue once more. Cannot loot the thugs, cannot continue the quest. I went ahead and defeated all other thugs I could find on the map, including the ones in the locked house, but I still can only answer "Not yet" to the quest-giver's inquiry as to whether or not I have taken care of the thugs.

 

Steps to Reproduce the Issue:

From the save file, try to loot the

 

Important Files:

https://www.dropbox.com/s/r2le0d3tnpe4lhg/PoE_Supply_and_Demand_bug_report.zip?dl=0