During a Thieves Guild quest entitled: Forever Hold Your Peace, I encountered a bug which prevented me from entering the palace which is your objective. The key itself is looted from servants in the area, and in the videos shown, you will see it is in my inventory (quest items). It has been well over 24 hours I have been trying to work around this bug, but nothing I or customer support has provided has worked. This includes: repairing client, /reloadui, disabled & uninstall addons, restart quest, restart computer, leave area and come back, even tried to do this on a different computer AND network, etc.
The most notable thing I can say about this bug is when you get the waypoint for entering the palace, it is not on the correct door, or any door for that matter. It's almost as if it's under the map. I have also seen several threads about this starting near the RELEASE of the Thieves Guild DLC. Which indicates that no one has taken the time to fix this. Which makes sense, because customer support seems to think that restarting my router or /reloadui will fix this. Videos included below. I will continue to update this for as long as I am sane.
https://youtu.be/QgJ_mO_MHcQ
https://youtu.be/-Fg-qxnHgeo