Indefinite amount of time used to save world

After exiting the world, the game entered the loading screen correctly, but never got past "Saving world." I have let it run for at least an hour so far. Clicking around on the game doesn't make it register as not responding, so I haven't received a prompt to force close it. I don't know whether or not forcibly closing the game will corrupt the world.

Normally, worlds save within 5-8 seconds at the worst, and given my hardware, this can't possibly be due to low resources. Minecraft is using 259-312 MB of RAM, gradually increasing and then returning to a lower value. This leaves me with more than enough RAM to run another instance of Minecraft 1.14, which hasn't had this problem.