Modpack is Enigmatica 6 Expert,
No Roadrunner or Optifine
BetterEnd Reforked installed
Tested with flywheel enabled and disabled
Exact same/ similar crash using magnesium and calcium
Crash still occurs on a fresh install

Crash Log with Rubidium
crash-2022-04-21_21.58.25-client.txt

Crash Log with Magnesium
crash-2022-04-21_15.07.24-client.txt

Fixed in 341dd61
Update Rubidium