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Fix Minecraft server lag and crashes

5 min readUpdated Oct 31, 2026

Find out why your Minecraft server lags or crashes and fix it: TPS, RAM, view distance, pre-generating, plugins and reading crash logs.

Is your Minecraft server lagging, freezing or crashing? Most of the time it comes down to one of a few things: not enough RAM for what the server is doing, too many players loading new land at once, a heavy plugin or mod, or a version mismatch. This guide shows you how to find which one it is and fix it. It works for Paper, Purpur, Fabric, Forge and Vanilla servers on ESN.

1. Server lag or your own connection? #

  • Server lag hits everyone at once: blocks pop back after you break them, mobs freeze, and the Console shows Can't keep up! Is the server overloaded?. The fixes on this page are for this kind.
  • Connection lag hits only some players: high ping, rubber-banding for one person while others are fine. That's usually their internet or Wi-Fi, not the server.
  • Not sure if it's ESN? Check the status page first.

2. Measure it: TPS #

A healthy server runs at 20 TPS (ticks per second). Below about 18 you start to feel it, and below 15 it's clearly laggy. On Paper and Purpur, type this in the Console (no slash) to see it:

tps

For a closer look, add the free spark plugin (see adding plugins), restart, then run a short profile while the lag is happening:

spark profiler start --timeout 60

After 60 seconds spark gives you a link. Open it to see which plugin, mob type or task is using the most time.

3. Check your RAM #

Your plan's RAM is the server's memory limit, and the panel sets it for you on start. Watch the memory graph on the server's Console page while players are on.

  • If memory sits near the top of your plan, or the Console shows OutOfMemoryError, the server needs more RAM or less load. See how much RAM a Minecraft server needs.
  • Don't add your own -Xmx above your plan's RAM in the startup settings. The server can't use memory the plan doesn't have, and it can crash when it runs out.
  • Modpacks and Forge servers need a lot more RAM than plain Paper. If you added mods recently, that's often the reason.

4. Lower view distance and simulation distance #

How far the server loads and runs the world around each player is the biggest setting for lag. Open server.properties in Files, change these, save and Restart:

view-distance=8
simulation-distance=6

Players still see a good distance, but the server does a lot less work. If it's still laggy, try 6 and 4. On Paper, more performance settings live in config/paper-world-defaults.yml, but distance is the big one.

5. Pre-generate your world #

Making new land is the heaviest thing a server does. When players fly around with elytra or explore fast, the server has to build new chunks nonstop. Pre-generating the world once fixes this:

  1. Add the free Chunky plugin (Paper/Purpur) or mod (Fabric/Forge) and restart.
  2. In the Console, set a size and start it. For example, a 3000-block radius around the center:
chunky radius 3000
chunky start

It runs in the background and can take a while. Run it when few players are online. A world border the same size stops players from going past the pre-generated area.

6. Plugins, mods and farms #

  • Too many or heavy plugins: the spark report from step 2 names them. Remove or replace the worst one, then test again. Fewer, well-made plugins beat many small ones.
  • Out-of-date plugins can lag or crash on a newer Minecraft version. Update them to a version made for your server version.
  • Huge mob farms and lots of item frames, hoppers or redstone clocks in one place add up. Spread them out or limit them.
  • Too many dropped items or mobs: kill @e[type=item] in the Console clears dropped items right away (it deletes them, so warn players first).

7. The server crashes or won't start: read the log #

When a server crashes, the reason is almost always written down. Open Files and look at:

  • logs/latest.log: the full log of the last run. Scroll to the bottom and look for the first ERROR or Exception line just before it stopped.
  • crash-reports/: a crash report file, named by date, is saved here when the game itself crashes. The Description line at the top and the first lines under it usually name the plugin or mod that caused it.

Common messages and what they mean:

  • OutOfMemoryError: not enough RAM. See step 3.
  • Unsupported class file major version or another Java error: choose a newer Java version in the Docker Image box on the Startup page. Newer Minecraft versions need newer Java.
  • Could not load 'plugins/…jar' or a mod named in the crash report: that plugin or mod doesn't match your server version or is missing something it needs. Update it or remove it.
  • Failed to bind to port: server-port in server.properties was changed. Set it back to the port shown on the Network page.
  • A world that crashes on load: restore a backup from before the problem started.

8. Keep it fresh with scheduled restarts #

A restart once or twice a day clears out memory and keeps long-running servers smooth. Set it up once with a schedule so it happens on its own, at a time when few players are online.

Still lagging? #

Note what you tried and your TPS or spark link, then ask in the ESN Systems Discord or contact support. If your server has simply outgrown its plan, a bigger plan on the plans page gives it more room.

Still stuck? Use the live chat on the panel or ask in the ESN Systems Discord. Last updated October 31, 2026.