Fixing Krypton Mod Conflicts and Crashes on Startup

Common Cause of Conflicts

Krypton rewrites Netty handlers and packet serialization. Any other mod that does the same — networking libraries, proxy-integration mods, or other optimization mods touching packet handling — can clash with it. Symptoms include a crash on startup, a crash when a player joins, or packets being dropped.

Diagnosing the Problem

Read the crash report or log. Look for the mod name in the stack trace near the top of the failure. If Krypton appears, temporarily remove the other networking-related mod and retest. If the crash disappears, you have found the conflict. Test on a clean instance with only Krypton and its required dependencies first, so you know Krypton itself is fine before adding everything else back.

Resolving It

If two mods both optimize the same networking path, keep the one that fits your setup. Krypton is designed to work alongside proxies like Velocity, so if you run a proxy, keep Krypton and drop a redundant networking mod. If you cannot identify the conflicting mod from the log, add mods back in small batches until the crash returns. Never assume a crash is Krypton's fault just because it is a performance mod — check the trace first.