For some reason, I found myself unable to load my world. I've been able to do so before, but when I try to now, the game just hangs, and upon closing Minecraft, I found a crash report. I tried again to verify, so see both attached crash reports:
crash-2018-01-19_19.45.38-server.txt
crash-2018-01-19_19.59.33-server.txt

You are using an outdated version, please update.