Minecraft: 1.18.2
Forge: 40.1.0
Hex Casting: 0.8.0 or 0.8.2 (tried both)
Patchouli: 67
Kotlin for Forge: 3.3.2-obf

Crash on startup. Crash report here: https://hastebin.skyra.pw/zizekuriqe.nestedtext

Using GDLauncher I get this as well:

This is very much not Hex's issue. Something's REALLY weird with your instance besides Hex itself.

While I'm not disputing what you say is true, enabling Hex Casting and Kotlin for Forge is the only thing that causes a crash. I'll see about disabling other mods and see what I can find out.

Is PAUCAL installed?

Nope. Just found the issue. It's not listed or related on the Curseforge page. That should do it.

They're marked as a relation on my end, but if memory serves GDLauncher won't grab dependencies like that.

You're right about the CurseForge page not listing it as a requirement, though. That'll be on @gamma-delta to fix.

Whoopsy, good catch 😅😅😅

Alright, it's on the CF page now. Thanks!