Meaning: Failed to create the thickened ruled surface geometry. The thickened surface will not display. Could not split the ruled surface at its discontinuities.
Redefine the base or top curve to eliminate discontinuities (knuckles).
Verify that all the inputs are properly identified. They must be of the type curve, point or an edge port.
Update any inputs that are on the To Do List.
If proper inputs are provided and the problem persists, report steps taken to your support group.