Seems at the ratio when the windows almost can’t be divided, the component will turn wrong and got the message:
“1. Solution exception:Local variable ‘rectWinBreps’ referenced before assignment.”
The pics below depict this:
A: WWR=0.48,windows are divided
C:WWR=0.50,turn to one single window
In fact the ratio 0.489 and 0.491 work fine. The exact 0.49 value for any face will go wrong.