Versions (Be specific, do not write "latest"):

• Curios: 1.19.3-5.1.4.0 and 1.19.3-5.1.4.1
• Forge/Fabric: 1.19.3-44.1.23

Observed Behavior: Server crashes with mixin,

Expected Behavior: server loads with curios enabled

Steps to Reproduce: Add Curios, setup the config and other folders and file per the User instructions

[27Apr2023 20:20:55.360] [main/DEBUG] [mixin/]: Mixing MixinLivingEntity from curios.mixins.json into net.minecraft.world.entity.LivingEntity
[27Apr2023 20:20:55.375] [main/WARN] [mixin/]: Error loading class: java/lang/Boolean (java.lang.IllegalArgumentException: Unsupported class file major version 64)

Crash Log: Please use a paste site like hastebin.
https://pastebin.com/DgQEZeCA
note: this log has multiple mods, but the same error occurs with only curios.

I believe your log says you're using Java 20. You need to use Java 17.