Amethyst Caves biome uses minecraft:music.overworld.jungle_and_forest which was removed in 1.20

[alcatrazEscapee]

The amethyst caves biome JSON specifies the music sound event as minecraft:music.overworld.jungle_and_forest:

Profundis/src/main/resources/data/profundis/worldgen/biome/amethyst_caves.json

Lines 12 to 17 in df25f41

	"music": {
	"max_delay": 24000,
	"min_delay": 12000,
	"replace_current_music": false,
	"sound": "minecraft:music.overworld.jungle_and_forest"
	},

However, this does not exist in 1.20. According to a brief search in Linkie, it seems to have existed in 1.19.4 then removed in 1.20:

In 1.19.4:

In 1.20 (and onwards):

Due to vanilla's poor codec handling, this field being invalid does not error, as the music field is an optional field. When used with Cyanide, however, this gets promoted to a full error:

[23:16:10] [Render thread/WARN] (Minecraft) Failed to load level data or datapacks, can't proceed with server load
java.util.concurrent.ExecutionException: java.lang.IllegalStateException: Error(s) loading registries:


Errors(s) loading registry minecraft:worldgen/biome:

Optional field "music" was invalid: Failed to get element ResourceKey[minecraft:sound_event / minecraft:music.overworld.jungle_and_forest]
	at: "effects"
	at: worldgen/biome 'profundis:worldgen/biome/amethyst_caves.json'
	at: pack 'fabric'


Errors occurred freezing registries.
These were elements that were referenced, but never defined (or their definition had an error above).

Missing references from the worldgen/biome registry: [
	'profundis:amethyst_caves'
]

This was reported as an issue to Cyanide here: alcatrazEscapee/cyanide#23