[1.20.1] Cannot load or create world with Upgrade Aquatic + Elytra Trims

[Diamondback88]

When attempting to load a world with Blueprint, Elytra Trims, Kotlin for Forge, and Upgrade Aquatic on recommended Forge version 47.1.3, the world will refuse to launch and only offer a "safe mode" option to launch the world. If you attempt to create a new world, the game will crash.

It's worth noting that this also happens on the latest NeoForge version for 1.20.1 (47.1.106); this is likely because this NeoForge version has parity with Forge version 47.1.3.

Steps to reproduce:

Install Blueprint, Elytra Trims, Kotlin for Forge, and Upgrade Aquatic.
Load an existing world.
Receive the error.

OR:

Install Blueprint, Elytra Trims, Kotlin for Forge, and Upgrade Aquatic.
Attempt to create a new world.
The game will crash.

Log:

https://mclo.gs/XHW4wIF