Reload chunks on your Minecraft server

Players say "the chunks are broken" for three different problems: terrain that looks wrong on one person's screen, an area where the server itself seems stuck, and a chunk that is actually damaged on disk. Each has a different fix, and the first two are quick. This guide takes them in order, so you can stop at the first one that works.

Checked against Minecraft 26.3, using Mojang's own client and server files, October 2026.

When it only looks wrong for one player

If one player sees missing patches of ground, holes in a build or blocks that look out of date, try the client's own reload first, because it costs nothing. Minecraft has a keyboard shortcut for it. The game's own key list reads "F3 + A = Reload chunks", and it shows "Reloading all chunks" when you use it. The player presses F3 and A together while in the world.

If the area is still wrong after that, look at the server side next.

When the server seems stuck

If part of the world seems frozen on the server, a restart is the simplest first thing to try, because the server then reads its chunks back from the world's region files.

1. Open the Console tab and type save-all. The game answers "Saving the game (this may take a moment!)" and then "Saved the game".
2. Click Restart. The server stops cleanly and starts again.
3. Wait for the Done line, then check the area.

Do not use Force stop for this. It skips the graceful shutdown, so anything the game had not saved can be lost. Keep it for when Stop hangs.

When a chunk is damaged

Look in the Console for a line like Failed to load chunk 12,-4. That means the game could not read that chunk. Fix corrupted chunks and region files shows how to find the file, restore it from a backup or let the game rebuild it. To redo a chunk on purpose, Reset or edit chunks with Amulet covers the tool for it.

When loading chunks causes lag

If the world only lags when players load a lot of chunks, such as when several explore at once, two things are worth trying:

• Open Config Editor under Content and look under Performance. View distance (chunks) and Simulation distance (chunks) both default to 10 and accept 3 to 32. The panel describes view distance as the single biggest lever on RAM and CPU, so lowering them is the first thing to try. Click Save changes and restart.
• Build the terrain ahead of time with Chunky, a tool for pre-generating chunks, so fewer chunks have to be created while players explore. Pre-generate a Minecraft world with Chunky shows how.

If you wanted the opposite, chunks that stay loaded when nobody is near, Minecraft chunk loaders: how they work covers it.

Keep a backup before you experiment

Anything that touches the world files, such as deleting a region file, is easier to undo with a backup. Click Create backup in the Backups tab first. Create and restore backups walks through it.