Minecraft Farms Not Working on a Paper Server: How to Fix It

Why it happens: Paper isn't the game as-is

Paper is a version of the official server built to run faster and to stop cheating. That's why it ships with the game bugs that let you duplicate items or break unbreakable blocks closed by default. In a single-player world that doesn't happen: the normal game allows them.

The settings that reopen them live in a section of config/paper-global.yml called unsupported-settings. The name warns you about something true: if you turn one on and something breaks, the Paper team won't treat it as their bug. For a group of friends playing technical Minecraft, turning them on is normal.

Which setting each farm needs

They all go in config/paper-global.yml, inside unsupported-settings, and they default to false. Only turn on the ones you need:

1. TNT, carpet or rail duper: allow-piston-duplication

   The most searched one. Careful: it doesn't only reopen TNT; it also lets you duplicate carpets, rails and a few more items with the same piston trick. On an SMP with an economy or shops, think it over first.

2. Sand or gravel duper through the End portal: allow-unsafe-end-portal-teleportation

   Farms that duplicate falling blocks (sand, gravel, anvils) by sending them through the End portal need this one.

3. Breaking bedrock or portal frames: allow-permanent-block-break-exploits

   To remove bedrock from the Nether roof or move End portals with the piston and TNT tricks.

4. Headless pistons: allow-headless-pistons

   Some advanced redstone machines and the bedrock breakers use them.

5. String or tripwire hook duper: skip-tripwire-hook-placement-validation

   For string farms based on the tripwire hook bug.

Slow mob farms: the activation range

If the farm isn't broken but slow (the iron farm makes fewer golems, the villager breeder barely breeds, the mob farm is weak), you're most likely too far from it. Paper inherits a saving from Spigot called entity-activation-range: mobs far from every player move and think much less often. By default it's 32 blocks for animals, monsters and villagers, 64 for raiders and 16 for water mobs and everything else.

What works best without changing anything: put each farm's AFK spot inside that range. If the design needs you further away, raise those numbers in spigot.yml (in the server's root folder, under entity-activation-range: animals, monsters, villagers, raiders, water, misc). The higher they are, the harder the CPU works: only raise the mob type your farm uses.

And don't forget the simulation distance (simulation-distance in server.properties): outside it the world doesn't tick and no farm produces anything, with Paper or without it.

If redstone behaves differently

By default Paper uses the same redstone as the game (redstone-implementation: VANILLA, in config/paper-world-defaults.yml, under misc). Some optimization guides recommend switching it to ALTERNATE_CURRENT or EIGENCRAFT: it's faster and almost every circuit works the same, but the ones that depend on the exact order redstone updates in can break. If your machine fails and someone touched that setting, set it back to VANILLA.

If your farms pile lots of mobs together so they push each other, the setting to look at is max-entity-collisions (8 by default), in the same file, under collisions: it limits how many others each mob collides with, to save CPU.

How to change it without breaking anything

This is how the section looks with the TNT duper and the sand duper turned on (the rest of the file stays the same):

unsupported-settings:
  allow-piston-duplication: true
  allow-unsafe-end-portal-teleportation: true

1. Make a backup

   On the server, «Backups» → create one. If it's the free server (it has no backups), download the config folder from «Files» first.

2. Stop the server

   With «Stop». Paper rewrites its files when it shuts down: if you edit them while it's running, it can overwrite your change.

3. Edit the file

   In «Files» open config/paper-global.yml (or spigot.yml for the activation range), find the line and change false to true. Keep the spaces at the start: indentation matters in these files.

4. Start it and test

   «Start» and watch the «Console»: if the file has a mistake, Paper says so on startup. Test the farm while standing close to it.

When Fabric is better

If your group lives on technical farms and doesn't use plugins, Fabric leaves the game as-is, without changing anything, and supports performance mods like Lithium (which also tries not to change how the game behaves). It's what many technical servers choose.

What you lose are Paper's plugins (land claims, EssentialsX, DiscordSRV…): Fabric uses mods, and not all of them have an equivalent. That's why, for a normal SMP with a couple of farms, turning on the two or three settings above in Paper is usually the easiest option.

With NapNodes

Minecraft servers are delivered on Paper, on the latest version, so everything in this guide applies as-is: the files are in «Files» and you edit them in your browser.

If you'd rather use Fabric, in «Mods & plugins», «Server type» tab, you switch without losing the world; plugins that no longer work are set aside (with the date in their name) instead of being deleted. Make a backup first.

Frequently asked questions