Game crashed, and at the time I was working on creating a new blueprint. I'd selected contents for the blueprint, and was modifying some of the stuff in it, but I hadn't 'saved' the blueprint yet. It could be totally unrelated to the crash though, as I loaded the last autosave and redid the blueprint without issue the second time, so I haven't been able to reproduce it (yet, anyway). No mods are used, other than the official "mods" that are Space Age.
Some probably unusual config I have:
Non-blocking saves are enabled
Texture compression is disabled
Let me know if there's anything else that would be helpful.