An program exception occurs when an unexpected event happens that requires special processing that it does not handle. In this case the the leader lines have no points so when we try to draw them there is an exception. Some exceptions can be handled silently so the user never sees them. In this case you don't get the message popping up but the drawing of the dynaview stops. We added code that will now allow the dynaview to continue to draw even if this object has an exception. As exceptions are not objects there is nothing to select. The leaders were probably created in autocad, then imported. The corruption should be handled on the object creation and fixed there.
You are correct that the program should not skip over the rotation angle. If you create the dynaview in plan view the program stops at the angle where the user can graphically pick the angle. When created in the sheet view it does not operate as intended. I have created an issue for this and should have it fixed for the next release.
tim