Early game there is a race condition where ships that require special resources can be double-clicked again in the "Available Ships" list even if you don't have the resources available.  At a guess, the game was lagging a bit at the time due to processing other things, so the "Available Ships" list did not update faster then I could double-click to add the "prototype" hull again.

The icon was blank for that line when I double-clicked on it.

Not sure how to make it crash again.  I would suggest a check on the build button and/or the double-click action to prevent the user from queuing up a ship that exceeds the available resources.