Hi kromerok

Please, check the pictures attached to follow the explanation. I used a hip connector for the example
For the clarity of the explanation, this hip connector has 3 pieces (each one of the directions of the pitch)
The shapes in red are showing the places where you can add a roof cutout, because each cutout is inside a single piece
The shapes in blue are showing the places where you can't add a roof cutout, because each cutouts is not inside a single piece
Therefore, the rule is: you can't add a cutout if the cutout is touching the eave, ridge, etc, therefore you will receive an error message

In addition, if you have a dormer in the eave, the cutout will not work, because the cutout has a border, so in the eave case (#3 in the image), I suggest the use of a freehand roof, and contour the dormer (green roof in the plan)

The cutouts and dormers can be used with any type of roof, including the roofs generated with the Roof Wizard

Hope this helps

Patricia