Custom dimension and chunk generator errors

Hi everyone. I was following McJty's tutorials on custom world generation tutorial for 1.18.2. The dimension is set up just fine but when I try to set its chunk generator type to the custom ones registered, I get two different errors depending on whether I join a new or old world. I made sure with print statements the registry of the chunk generator existed and the path matched the one in the JSON files and everything is fine. I thought the problem was with the codec of the generator class but even using the built in codecs from NoiseBasedChunkGenerator in registering my own led to the same error. 

Error trying to create a new world: leads to safe mode or back to title screen buttons.

debug.log

Eclipse output log

Error trying to load chunks in custom dimension in a previously working world:

debug.log

Here it's flat ocean when I go to unloaded chunks in the dimension I made.

Mod files here (GitHub). Including the custom biome source in the dimension JSON file resolved the ocean issue but it's not the intended chunk generation. The files to look at are probably DimensionInit (init package), ChunkGen, and BiomeProvider (world/biome package)

Any help would be greatly appreciated, as well as any bad habits to break if seen. I'm new to coding with forge but not coding in general.