I was playing in my Hardcore world on 1.18-pre1 and I was running along the land when my game suddenly crashed while heading north. When I re-entered my world I was spawned in at a location that I was at about 5 minutes prior to the crash. I tried going back and my game crashed at the same Z coordinate 3 different times, and each time I spawned back in, I was at the same previous location.

This is the crash error message:
The game crashed whilst feature placement
Error: java.lang.NullPointerException: Cannot invoke "ddm.a(cao, cps, java.util.Random, gh)" because the return value of "java.util.function.Supplier.get()" is null
Exit Code: -1

I'm not sure if you can really "fix" my world but if there is a fix I'd love to hear it. I also just wanted to let you guys know about this issue so that you can fix it before the full release of 1.18!