Warning

NoClassDefFoundError / ClassNotFoundException — fix mod conflicts

Example error line

java.lang.NoClassDefFoundError: some/Mod/Class

Cause

A required class is missing — a mod/plugin expects another mod or a different version that is not installed.

Fix

Check the mod/plugin's dependencies and versions; install the missing dependency or a matching build.

Learn more

Paste your full crash report or log excerpt into our analyzer and get an instant diagnosis for every pattern it recognizes.

Choose the right game server and review its resources, settings, and final monthly price before ordering.