Error: game.data.chunk.Chunk.getChunkHeightHandler()" is null

[pdpatel13]

I was trying to do this using the command-line, I'm not sure exactly if it's a problem with how I'm doing it or if it's because there's an error, the error message repeats every couple seconds. Full error message: java.lang.NullPointerException: Cannot invoke "game.data.chunk.ChunkHeightHandler.heightAt(int, int)" because the return value of "game.data.chunk.Chunk.getChunkHeightHandler()" is null
at game.data.WorldManager.checkAboveSurface(WorldManager.java:194)
at game.data.WorldManager.save(WorldManager.java:421)
at game.data.WorldManager.save(WorldManager.java:467)
at util.ExceptionHandling.attempt(ExceptionHandling.java:12)
at util.ExceptionHandling.attempt(ExceptionHandling.java:22)
at game.data.WorldManager.lambda$start$3(WorldManager.java:417)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:577)
at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:358)
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
at java.base/java.lang.Thread.run(Thread.java:1589)

Command: java -jar world-downloader-2.jar --no-gui -s www.server.com