On version 0.199.528, shipyards are a bit broken. They disconnect my client when attempting to undock a ship that has been created and then cause class cast exceptions when attempting to load another design. I also had an error where it stated the design was too large for the shipyard, but it clearly wasn't. I was doing the experiment on the copy of the LvD world on the dev server at sector 2000, 2000, 2000.
Crash to main menu: