UnitListCodec encodes a ListTag instead of a CompoundTag, which breaks the call to buf.writeWithCodec inside SerializableDataType(Class dataClass, Codec codec)

Similar changes will probably need to be done to the receive method.

Worked around by reimplementing the writeWithCodec and readWithCodec methods to not have a hardcoded NbtCompound requirement.

This is most likely a temporary fix as ideally we'd turn the UnitListCodec into an entire object instead of a list for serialisation.