Have you tried download Black Emporium from your DLC page on the BioWare site?
https://social.bioware.com/user_entitlements.php
Regarding your fullsreen/window issue, I just launched Dragon Age II to see if alt+enter would work, only to get the error "another application is preventing you from running DA2 in fullscreen". This is the first i've heard of the issue, but I'll try to figure out a fix.
Edit: I only have the fullscreen issue if I launch directly from the executable. It launches fine through the Origin client. In my case, I believe it's caused by an overlay in Windows 10. In any event, switching to fullscreen in the game options works regardless of how I launch the game.