To further troubleshoot the error I've run up against (some custom designed ships lock the game up once they are finished being built), I got rid of all my custom designs, leaving only my custom base designs, and played a cakewalk game on a tiny map. I still got the error when deleting a ship component in the designer where the space numbers grow to serveral digits in length. I was able to build custom constructors and freighters, but my fighter locked up the game. Wanting to actually finish the game, I just built one constructor after another and put influence bases all over the map. Perhaps it has something to do with weapon components?
-Ryan