I've had this happen twice in a row.

I've loaded the game, and started a new game with a custom race on a small map, all other setting at their default. Created a ship in the ship designer, rushed it, and advanced one turn. On attempt 1, I exited to main menu and loaded the save game I am actually playing, went through my turn maintenance, then realized I needed to design a new ship. I entered the designer, and clicked on "New Design"  and the game seemed to freeze, the cursor turned into a circle and I got the "program has stopped working' windows dialog.

On the second attempt, I directly loaded my saved game from the game I was aborting, and immediately went into the designer. When I clicked on New Design this time, the game cleared ships, giving me a blank shipyard background for a couple seconds then crashed to desktop.

On a third attempt I loaded my game from the main menu, and the designer worked as always.