Replacing wall

[Wiki27]

I have been trying to change the wall paper in the left side of the corner wall, but the paper keeps defaulting to the right corner wall. It's the same with any item I try to place in that part of the wall. Does Any one know how to get around this.

[Unregistered]

I'm not sure about the wallpaper but I wasn't able to put a window there even though i've seen it done in other bakeries.