Chunks stop loading / render slowly / there's a map border far from spawn — how do I fix it?

If chunks stop loading, render slowly as you move, or you hit an invisible wall far from spawn, you're looking at one of a few distinct causes — usually performance-related generation lag or a world border. Here's how to tell them apart and fix each.

Common causes

• Slow chunk loading while moving is generation lag — the server is building terrain in real time as you explore.
• A hard, invisible "wall" is the world border, a configurable limit on world size.
• On modded servers, some dimensions have generation quirks that show up as chunk errors in the Console.
• Low view/simulation distance limits how far chunks tick and render.

How to fix it

1. If chunks load slowly as you travel, pre-generate the world with Chunky, and raise your plan if you're CPU-bound.
2. If you've hit a wall, it's the world border — check it with /worldborder get and expand it with /worldborder set <size>.
3. On modded servers, open the Console and look for chunk errors tied to a specific dimension or mod.
4. If you have CPU/RAM headroom, raise view-distance and simulation-distance slightly so chunks tick and render farther out.

Tip: A neat, perfectly circular or square boundary is almost always the world border, not a bug — expanding it with /worldborder set fixes it instantly.

Frequently asked questions

Why is there a wall far from spawn? That's the world border. Check its size with /worldborder get and expand it with /worldborder set <size>.

Chunks render slowly only when I move fast — why? That's generation lag. Pre-generate the area with Chunky so the terrain already exists, and consider a faster tier if you're CPU-bound.