A mod is calling game code that moved
What it looks like in your log
java.lang.NoSuchMethodError: 'void net.minecraft.world.entity.Entity.setPos(double, double, double)'
What causes it
A mod or plugin was compiled against a different Minecraft version, so a method it calls does not exist here.
How to fix it
The first mod or plugin class in the stack trace is the culprit. Install its build for this exact Minecraft and loader version.
Why it happens
A mod or plugin was compiled against one version of Minecraft and is running on another. It calls a method by its exact signature, and in this version the method has a different signature, a different name, or does not exist. Java finds out at the moment of the call and throws. Because the method is in net.minecraft, the game is not at fault; the caller is.
The first frame in the stack trace that is not net.minecraft, org.bukkit or java.* is the caller. That is the mod or plugin to update.
Fix it step by step
- 1Read the stack trace to the first non-game frameBelow the NoSuchMethodError line, skip every net.minecraft and java frame. The first package that belongs to a mod or plugin is the culprit.
- 2Match its build to the serverOpen its download page and install the build for your exact Minecraft version and loader. A build for 1.20.1 on a 1.20.4 server does this.
- 3Check for a stale libraryOn Forge and NeoForge, a mod that ships a library mod at an old version can shadow the newer one another mod needs. Remove duplicate library jars.
- 4Restart and repeat if neededAfter an update several mods can be behind at once. Fix them one at a time in the order the errors appear.
If that didn't work
NoSuchFieldError is the same problem for a field instead of a method. Same fix.
Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.
Check your own log