When the draft angle and the height are such that the resulting sweep surface would have self intersections, like the one in the following illustration, if you for example define a 40° draft angle and set the height to 400:
the self intersections are automatically trimmed and no error occurs:
A specific "Self intersection" warning is displayed on the model in the position where the problem occurs. You can hide the warning by clicking on the icon, that will turn to .
See an example in Managing Warnings.