Error Behaviour

When server is setup using the instructions on the modpage, clients are unable to connect to the server, giving the above error.

Further info:

• OS: Fedora 37
• Using Java 8 (System is configured to use 17, although this server is using package java-1.8.0-openjdk-1.8.0.362.b09-2.fc37.x86_64)
• 16Gb of RAM allotted to the server.

Expected Behaviour

Clients should correctly connect to server.

Reproduce

1. Install client modpacks using ATLauncher or FTB.
2. Server is setup by copying over mod files (excluding client mods as said on the mod-page) and other associated files.
3. Run server.
4. Connect with clients.

Crash Report

https://cdn.discordapp.com/attachments/871133788124635209/1124789469531361290/console.tar.xz

Modpack version

0.5.5-stable1-hf1

Server version

forge-1.16.5-36.2.39

Other mods and plugins

Using latest Optifine for 1.16.5, although friend without it encountered same error.