I have a player that says all the work they did last night has been reverted to the original chunks. I manually restarted the server this morning, but there has been no crashes or other oddities. The server hasn't been under load and there's been no plugin changes in the last few days. I haven't heard of a problem like this since early spigot releases where chunks were unloaded before being saved to disk. I'm not sure how to verify or debug this... but i wanted to start a thread incase anyone else noticed a similar thing.