David,
The slab that creates the hole in the wall, with the ID WALLHOLE, has to be the same shape as the window frame, whatever that shape is. If you do not have a slab shaped as the frame with the ID WALLHOLE engulfing the whole window, then what you are showing happens.
The default louvered window is only rectangular.
See the Window making part of the Reference manual, and search for WALLHOLE on the Talk, you will find the explanations!
HTH,
Djordje
ArchiCAD since 4.55 ... 1995
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