Just import it to a world. You'll see. Crashes instantly.
:info: Info
If you put something much lower (for example -480), it no longer crashes, but doesn't generate anything at all apart from amethyst geodes.
Stack trace
21w08b\: [^crash-2021-02-28_16.43.53-server.txt]
Description: Exception initializing level
java.lang.ArrayIndexOutOfBoundsException: -1
at ckf.b(SourceFile:62)
at cnl.a(SourceFile:444)
at cnl.b(SourceFile:370)
at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source)
at java.util.concurrent.CompletableFuture$AsyncSupply.exec(Unknown Source)
at java.util.concurrent.ForkJoinTask.doExec(Unknown Source)
at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(Unknown Source)
at java.util.concurrent.ForkJoinPool.runWorker(Unknown Source)
at java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source)
Here is a datapack that lowered the world's min y to -192. Here, no blocks are placed above sea level
[media]image:
[media]The experimental worldgen datapack being shared on Mojang's website compensates for this bug by setting 384 as the height. In retrospect, it really means height from bottom of world and not max y. Even though this is more of a feature request, I'm putting this here for any other user that may try to lower the world and face this issue and come here. Hopefully height will be changed to height_range or max_y instead to stop the confusion