Server Won't Start or Keeps Crashing? What to Check First

Most crashes come from one recent change (a mod, an update, a startup setting) or from a problem on the machine your server runs on, which only we can fix. Work out which one it is before you change anything else.

Before you change anything

1. Stop the server and archive its files. See Back Up Your Server Files Manually. If the File Manager won’t load, skip this and go to Step 1.
2. Start it once, not over and over. Starting it again without a change crashes it the same way.
3. Don’t reinstall or Format just to get past a crash. A reinstall rarely fixes one and can overwrite files we could otherwise recover, and Format permanently deletes your world, configs, mods, and plugins. The guides linked below tell you when a reinstall is the actual fix.
4. Don’t switch versions or server software to get around a crash. On Minecraft, a world opened on a newer version can’t go back.
5. Don’t delete the world. Rename the world folder instead (for example, world to world.old) so you can bring it back.
6. Don’t upgrade RAM yet. It only helps an out-of-memory crash, and Step 2 tells you if it is one.

Step 1: Can the panel reach your server?

If the panel can’t reach your server, you can’t fix it from your side, and we need to look. Signs:

• An error status instead of running or offline
• A blank console, and CPU Usage and Memory Usage graphs with no readings
• A File Manager that won’t load

Check the Status Page, then contact support with your Server UUID. Don’t reinstall, and don’t keep pressing Start or Kill.

A new server with no console output for 15 minutes, or one that shows Install Failed, also needs us. See First Run or “Install Failed” When Opening Your Server.

Step 2: Read the crash notice

When the server process stops on its own, the panel posts a crash notice in the Console. Copy it before you do anything else, then check what it tells you:

What you see	What it means
It says the server ran out of memory, or shows exit code 137	The server went over its memory limit. Go to Out of Memory (OOM) Crashes.
No sign that it ran out of memory	Something else stopped it. Go to Step 3.
A link to the crash log	Save it for support.

For what a specific exit code means (1, 133, 137, and others), see Server Crashed With an Exit Code.

Server keeps restarting on its own? In the sidebar, open System > Audit Logs. If it lists a crash each time, read each crash notice, not just the last one.

Missed the notice? Click Upload logs beside the console for a link to the current log (see Console).

Step 3: Find the first error

Open the crash log link or your Upload logs link. If the server dies while starting, find the first line with ERROR, FATAL, or Exception. If it crashed while running, read the lines just above the crash notice. On Minecraft, logs/latest.log in the File Manager holds the full log. If Minecraft also wrote a crash report, it’s in the crash-reports folder.

What you see	What to do
OutOfMemoryError, “Killed”, or exit code 137	See Out of Memory (OOM) Crashes.
Not enough disk space!	Free some space or ask us for more. See Unmetered Storage.
The error names a mod or plugin, or the crashes started right after you added one	Remove the newest addition and start once. Can’t tell which one? See Find Which Mod or Plugin Is Causing Problems.
Minecraft, after a modpack, software, or version change	See Fix a Broken Modded Server.
Minecraft: Unsupported class file major version	Wrong Java Version. See Java Version Selection.
Minecraft: Unable to access jarfile, or it starts as plain Vanilla	The server software install doesn’t match. Leave Server Jar File as the panel set it, and see Check Java and the server jar.
A fatal error has been detected by the Java Runtime Environment	Undo any mod or Java Version change you just made. If nothing changed on your side, contact support.
The console stops printing and the server never finishes starting	Something hung while loading, often a mod or a config file with a typo. Click Stop (use Kill only if Stop doesn’t respond), undo the last mod or file edit, then start once.
An error about the world or save file, or the world won’t load after an update	Don’t delete it. Restore a backup.

Get back to a working server

Work down this list and stop at the first step that works:

1. Undo the last change. Remove the mod or plugin you added, put back the file you edited, or set the Java Version or Server Options value back.
2. Restore your archive from Before you change anything.
3. Ask us to restore a WinterNode backup. Message us on Discord or open a Client Area ticket with your Server UUID and when the problem started. Our support team will restore the backup from before it and, if you ask, put the files back in place for you. Replies average about an hour. How backups work: Minecraft Java, see Backing Up Your Minecraft Java Server. Other games, see WinterNode Backup System.

Still Not Working?

Contact us when Step 1 points to our side, when Java itself crashed and nothing changed on your side, or when you can’t tell what the error means. Send us the log before you reinstall anything. We’d rather read it with you than have you lose files. Reach us on Discord or in a Client Area ticket with:

• Your Server UUID
• The crash log link from the crash notice, or from Upload logs
• When it started, with your time zone
• What changed just before: a mod, an update, a setting, a file you edited, or nothing
• What you’ve already tried, especially a reinstall, Format, or a version change