https://pastebin.com/3Y7cvWCS

Something about a blasting recipe and duplicate keys

MC 1.16.3
forge-1.16.3-34.1.42
ElementalCraft 1.16.3-2.4.0

Do you have a modpack export ?

Seems to be able to generate a world but crashes after trying to load in, I've deleted all the worlds after each attempt but seems to happen every time I create a new one. export is multiMC but I assume it'll work with Twitch
dl
I only put the important stuff in as everything else should be default

fixed in 1.16.3-2.4.1

Can confirm issue gone. Thanks for the quick fix!