Using and only happens on Embers UEL 1.21.0, the earlier version works with no crash
crash report: https://mclo.gs/jNmS8hw

bravo! will try it right away. if i got it right i no longer need soot in my instance?

Yep should work without it now.

I just released a new beta version on curseforge, that merges soot into the base mod. Maybe you can give it a try and report back any issues you encounter!

https://www.curseforge.com/minecraft/mc-mods/embers-extended-life/files/5118405

Getting this crash on startup
https://mclo.gs/nxLM7ul

Yep 1.21 introduces our registry refactor. We're already working on integrating soot as the first addon module in our fork. For now stay on 1.20.1 if you don't want to disable soot for now.