As Wildlands is my favourite map, I've played this one a lot and the Shroud city issue is present in more maps as well, so I think it's probably a universal bug of the Shroud.
1. The city has no defenders at all.
2. The city when captured usually prevents 'end turn' from being pressed. Only work around - save, then reload.
3. Capturing the city does not get recognised as finishing the quest. This leads to the city sitting inside the shroud wildland borders with no area at all around the city. I.e. you cannot build buildings etc requiring map tile space as wildland borders prevent this.
4. If you take a monster lair in the shroud after capturing the city (I believe any monster lair at random) then it triggers the quest ending and all is 'fine' from this point onwards.
Unfortunately this completely ruins the map as the advantage of capturing this city leads to an incredible lead over other races. If it was difficult to take the city - great. As it stands, it kills the game. As this is a fantastic map otherwise it's a real shame. Tried to modify the map in the map editor, but can't find any method of actually removing or better yet replacing the wildland with another type. HELP!
Would be great to have a fix to this as it really renders all maps where the Shroud is present useless and considering it's part of the 'map pack' which didn't exactly contain a massive amount of maps it's a large percentage of the product bought that is not functional. Any heads up on when this bug could be fixed would be much appreciated!