I ran into an unexpected problem with a window where I wanted to assign the lightSourceMaterialName property to a part of a window. The problem is simple: you can't set the property in the Furniture Library Editor when the object is a Door or window.
I tried to cheat by manually adding the lightSourceMaterialName property in the library properties file but of course that didn't work.

I can't think of any logical reason why this shouldn't work for a window. For a staircase it does work. I tried it, the library property is available and there's a power property when you modify the staircase. A lighted side panel looks good in a render!

Is there a reason why this doesn't work for a window or is this a bug?