Cannot place windows in a wall

[Soundsman]

When I try to add windows to the building the window icon shows but when I place it and left click to set it in the wall it just vanishes. 

I have tried multiple window types and sizes and they all act the same way. 

I need windows, can anyone please help. 

[Gekker]

Hello, the "Adding Windows and Doors" section of the user's manual can be found at http://help.nchsoftware.com/help/en/dreamplan/win/adding_windowsanddoors.html

Basically, select a window and place it with left click, If you have issues with this,  enter a detailed support ticket at http://www.nch.com.au/support/index.html