Ah, one more thing that may help track this down. Even when the designer would successfully load a ship, it would be extremely laggy. I'm talking I can walk away from the computer to refill my water bottle (~30 seconds) and sometimes it hasn't finished loading the design by the time I come back.
I wanted to chime in and say that I'm having the same issue. Most times when I click on a ship (any ship!) in the designer, it locks up my system. Sometimes, it works... at first I thought it was the custom hulls that I was having a problem with, as I downloaded some from the workshop way back in 1.2 and maybe they were causing crashes, but it's definitely happening with stock hulls as well. Twice today I've opened a saved game, gone immediately to ship designer, and had it lock u