When you're piloting a vessel and switch to build mode, if you use the Radial Menu to select the Ship option, you get a consistent game crash with a null pointer exception. I first encountered this when working on a ship that I had created in a single-player world prior to the 0.199.234 update. I was unable to reproduce this on a ship that was newly created.
//I also don't appear to be able to add an attachment to this ticket...that could be a problem.//