Server crashes are one of the most frustrating issues Minecraft server owners face. Whether your server won't start, crashes randomly during gameplay, or shows cryptic Java errors, understanding how to read and analyze server logs is the key to fixing these problems. This comprehensive guide will teach you how to diagnose and fix the most common Minecraft server crashes.
Instant Log Analysis Tool
Don't want to manually read through logs? Our free Minecraft Log Analyzer instantly identifies errors, crashes, and issues in your server logs and provides solutions.
Analyze Your Logs Free →Table of Contents
1. Understanding Minecraft Server Logs
Minecraft servers generate detailed log files that record everything happening on your server. These logs are your primary tool for diagnosing issues. Understanding log levels helps you quickly identify problems.
Log Levels
Normal server operations. Players joining, commands executed, chunks loading.
Potential issues that don't stop the server but may indicate problems.
Significant problems. Plugins failing, exceptions thrown, features broken.
Critical errors that cause the server to crash or fail to start.
Log Entry Format
Each log entry follows a standard format:
[HH:MM:SS] [Thread/LEVEL]: Message
[14:32:15] [Server thread/INFO]: Player123 joined the game
[14:32:16] [Server thread/WARN]: Can't keep up! Is the server overloaded?
[14:32:17] [Server thread/ERROR]: Exception in plugin MyPlugin2. Where to Find Your Server Logs
Latest Log (Real-time)
The current session's log is stored in logs/latest.log. This file is overwritten each time the server restarts.
Archived Logs
Previous logs are compressed and stored in the logs folder with date-based names:
logs/
├── latest.log # Current session
├── 2026-01-02-1.log.gz # Previous sessions (compressed)
├── 2026-01-01-1.log.gz
└── 2025-12-31-1.log.gzCrash Reports
When a fatal crash occurs, Minecraft generates a detailed crash report in thecrash-reports/ folder. These files contain stack traces, system information, and the exact cause of the crash.
💡 Pro Tip: Upload your latest.log or crash report to our free Log Analyzer tool to instantly identify all errors and get suggested fixes.
3. How to Read Crash Reports
Crash reports can look intimidating, but they follow a predictable structure. Here's how to read them:
Crash Report Structure
---- Minecraft Crash Report ----
Time: 1/2/26 2:30 PM
Description: Ticking entity
java.lang.NullPointerException: Ticking entity
at com.example.plugin.EntityHandler.onTick(EntityHandler.java:45)
at net.minecraft.server.World.tick(World.java:123)
...
-- System Details --
Minecraft Version: 1.21.1
Operating System: Linux
Java Version: 21.0.1
Memory: 4096MB allocated
Plugins: EssentialsX, LuckPerms, MyPluginKey Information to Look For
- Description: Brief summary of what caused the crash
- Exception Type: The Java error (NullPointerException, OutOfMemoryError, etc.)
- Stack Trace: Shows exactly where the error occurred (look for your plugin/mod names)
- System Details: Server version, Java version, installed plugins/mods
4. Most Common Server Crashes & Fixes
OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap spaceCause: The server ran out of allocated RAM. This is one of the most common crashes.
Solutions:
- Increase allocated RAM in your startup flags (
-Xmx4G→-Xmx6G) - Use our Startup Flags Generator for optimized memory settings
- Remove memory-heavy plugins or reduce loaded chunks
- Pre-generate your world to reduce chunk generation load
Ticking Entity / Ticking Block Entity
java.lang.Exception: Ticking entity
Description: Ticking block entityCause: A specific entity or block (often from mods) is causing errors during its tick cycle.
Solutions:
- Check the crash report for the entity/block type and coordinates
- Use MCEdit or NBTExplorer to remove the problematic entity
- If modded, update or remove the mod causing the issue
- Roll back to a recent backup before the corruption occurred
Server Won't Start - EULA Not Accepted
[Server thread/INFO]: You need to agree to the EULA
[Server thread/INFO]: Go to eula.txt for more info.Cause: Minecraft's End User License Agreement hasn't been accepted.
Solution:
- Open
eula.txtin your server folder - Change
eula=falsetoeula=true - Save the file and restart the server
Port Already in Use
[Server thread/WARN]: **** FAILED TO BIND TO PORT!
Perhaps a server is already running on that port?Cause: Another process is using port 25565 (or your configured port).
Solutions:
- Check if another Minecraft server instance is running
- Change the port in
server.properties - On Linux:
sudo lsof -i :25565to find the process - On Windows:
netstat -ano | findstr 25565
Can't Keep Up! Server Overloaded
[Server thread/WARN]: Can't keep up! Is the server overloaded?
Running 5023ms or 100 ticks behindCause: The server can't process game ticks fast enough (target is 20 TPS).
Solutions:
- Use optimized startup flags (Aikar's flags)
- Reduce view-distance in server.properties (8-10 is recommended)
- Limit entity counts with plugins like ClearLagg
- Use Paper or Purpur instead of vanilla/Spigot for better performance
- Upgrade to a dedicated server with better CPU
Experiencing One of These Crashes?
Upload your server log to our free Log Analyzer and get instant diagnosis with specific solutions for your exact error.
Analyze Your Crash Report →5. Java Errors Explained
Understanding common Java exceptions helps you diagnose issues faster:
| Exception | Meaning | Common Cause |
|---|---|---|
| NullPointerException | Code tried to use something that doesn't exist | Plugin bug, missing dependency |
| OutOfMemoryError | Server ran out of RAM | Not enough RAM allocated |
| StackOverflowError | Infinite loop or recursion | Plugin bug, circular dependencies |
| ClassNotFoundException | Required class/library not found | Missing dependency, wrong version |
| NoClassDefFoundError | Class existed at compile but not runtime | Incompatible plugin versions |
| IllegalArgumentException | Invalid data passed to a method | Corrupted config, bad input |
| IOException | File/network operation failed | Disk full, permissions, network issues |
6. Diagnosing Plugin Conflicts
Plugin conflicts are a common cause of server instability. Here's how to identify and resolve them:
Signs of Plugin Conflicts
- Server crashes when specific actions occur (commands, events)
- Error messages mentioning plugin names in the stack trace
- Features from multiple plugins not working correctly
- "Plugin X has been disabled due to an error" messages
Binary Search Method
To find the problematic plugin:
- Remove half of your plugins and restart
- If the problem persists, the issue is in the remaining half
- If the problem stops, it's in the removed half
- Repeat until you isolate the problematic plugin
Common Plugin Conflicts
- Multiple economy plugins: Use Vault as a bridge
- Multiple permission plugins: Only use one (LuckPerms recommended)
- Chat formatting conflicts: Configure priority in each plugin
- Protection plugins: WorldGuard + GriefPrevention need careful configuration
7. Fixing Modded Server Crashes
Modded servers (Forge/Fabric) have unique crash scenarios:
Version Mismatches
The most common modded server issue. Ensure:
- All mods are for the same Minecraft version
- Forge/Fabric loader version matches mod requirements
- Client and server have identical mod versions
- Required dependency mods are installed (check mod descriptions)
Missing Dependencies
[FML]: Missing required mod: architectury
[FML]: Mod XYZ requires architectury 6.0.0 or higherSolution: Download and install the listed dependency mod.
ID Conflicts
Some mods conflict when they use the same internal IDs. Check mod configurations and adjust IDs if the mod supports it.
8. Preventing Future Crashes
Regular Backups
Automate daily backups. When crashes corrupt data, you can restore quickly.
Use Paper/Purpur
Optimized server software with better error handling and performance.
Monitor TPS
Use /tps command regularly. Low TPS often precedes crashes.
Update Regularly
Keep server software and plugins updated for bug fixes and security patches.
Allocate Proper RAM
Use our RAM Calculator to determine optimal allocation.
Test in Staging
Test new plugins/mods on a staging server before deploying to production.
Conclusion
Server crashes are frustrating, but with the right knowledge and tools, you can diagnose and fix most issues quickly. Remember to always check your logs first, look for error messages, and work systematically to isolate problems.
For quick diagnosis, use our free Minecraft Log Analyzer which automatically identifies errors and provides specific solutions for your server issues.
Helpful Tools
Tired of Server Crashes?
Our dedicated Minecraft hosting includes 24/7 monitoring, automatic crash recovery, and expert support to help you fix any issues. Plans start at $4.99/month.