Apparently, Mojang decided to make TitleScreen.COPYRIGHT a private member, so this 3a713a1 does not work anymore.

I could do a PR but I'm not very familiar with the project, I believe this is a quick fix.

Here's some of the log:

Time: 2024-06-10 17:20:07
Description: Rendering overlay

java.lang.IllegalAccessError: class com.terraformersmc.modmenu.event.ModMenuEventHandler tried to access private field net.minecraft.client.gui.screen.TitleScreen.COPYRIGHT 

Not sure what you're talking about, are you trying to run the 1.18.2 version of Mod Menu on 1.20.6?