Jellyfish failing to spawn

[DarianLStephens]

Whenever a jellyfish attempts to spawn, the following error appears in the log:
https://pastebin.com/MhQ4YQp5

The same error appears when attempting to use a Spawn Egg for a jellyfish, but with references to the Spawn Egg and placing an item:
https://pastebin.com/2Djbxe95