Not sure which of your mods is actually causing this, just updated everything to the latest requirements (as per the changelogs)

https://mclo.gs/lORDzEs

Fixed in ReachFix-1.12.2-1.1.1, RenderLib-1.12.2-1.4.1, Nothirium-1.12.2-0.4.1-beta, RLTweaker-1.12.2-0.7.1

Got this same crash again when updated to 1.1.2 on a dedicated server, mentioning Universal Tweaks.
Edit: This was due to mismatching ASMUtil.