# Minecraft Server Troubleshooting Guide: Common Problems and Fixes (/docs/minecraft/common-issues) This is the **starting point for any Minecraft server problem**. Each row in the tables below points to a detailed guide for the specific issue. If you're not sure what's wrong, scan the symptoms below and click through to the matching fix. Server Won't Start [#server-wont-start] | Error in Console | Cause | Fix | | --------------------------------------------------- | ------------------------------- | ---------------------------------------------------------------------------------------------- | | `You need to agree to the EULA` | EULA not accepted | [Accept the EULA](/docs/minecraft/agree-to-eula) | | `UnsupportedClassVersionError` | Wrong Java version | [Java Version](/docs/minecraft/java-version) | | `OutOfMemoryError` / Exit code 137 | Not enough RAM | [How Much RAM](/docs/minecraft/how-much-ram) | | `Failed to bind to port` / `Address already in use` | Port conflict | Restart from Dashboard, contact support if persistent | | Crash on plugin load | Incompatible or broken plugin | Remove the most recent plugin, see [Server Won't Start](/docs/minecraft/fix-server-wont-start) | | `Failed to check session lock` | Lock file from unclean shutdown | [Session Lock](/docs/minecraft/fix-session-lock) | | `Exception in server tick loop` | Watchdog killed a hung tick | [Server Tick Loop](/docs/minecraft/fix-server-tick-loop) | | `Ticking entity` crash | Corrupted entity in world | [Fix Ticking Entity](/docs/minecraft/fix-ticking-entity) | | Crash with no clear error | Read first error in log | [Server Won't Start](/docs/minecraft/fix-server-wont-start) | Can't Connect [#cant-connect] | Error in Minecraft client | Cause | Fix | | ---------------------------------------- | -------------------------------- | -------------------------------------------------------------------- | | `Connection refused` | Server offline, wrong port, full | [Connection Refused](/docs/minecraft/fix-connection-refused) | | `Connection timed out` | Wrong IP, DNS, network blocking | [Connection Timed Out](/docs/minecraft/fix-connection-timed-out) | | `Can't resolve hostname` | DNS misconfigured | [Custom Server IP](/docs/minecraft/custom-server-ip) | | `Outdated server` / `Outdated client` | Version mismatch | [Switch Version](/docs/minecraft/switch-version) | | `Failed to verify username` | online-mode mismatch | [Failed Verify Username](/docs/minecraft/fix-failed-verify-username) | | `You are not whitelisted on this server` | Whitelist enabled | [Whitelist Setup](/docs/minecraft/whitelist-setup) | | `Server is full` | max-players reached | [Player Limit](/docs/minecraft/player-limit) | | `You are banned from this server` | IP or name ban | [Ban / Unban Players](/docs/minecraft/ban-unban-players) | | `Kicked for flying` | Anti-cheat false positive | [Kicked for Flying](/docs/minecraft/fix-kicked-for-flying) | Lag and Performance [#lag-and-performance] | Symptom | Type of lag | Fix | | ------------------------------------ | --------------------- | ------------------------------------------------------------------------------------------------------- | | Everyone lags simultaneously | Server (TPS) | [Optimize Server](/docs/minecraft/optimize-server) | | TPS below 18 in `/spark tps` | Server (TPS) | [Setup Spark](/docs/minecraft/setup-spark) → find culprit | | One player lags, others don't | Network (player ping) | Player's local network | | Stuttering when exploring new chunks | Chunk generation | [Pre-generate Chunks](/docs/minecraft/pregenerate-chunks) | | Lag near a mob farm | Entity tick load | [Mob Spawn Rate](/docs/minecraft/change-mob-spawn-rate), [FarmControl](/docs/minecraft/optimize-server) | | `Can't keep up!` warnings | Server overloaded | [Server Tick Loop](/docs/minecraft/fix-server-tick-loop) | | Frequent OOM kills | RAM pressure | [How Much RAM](/docs/minecraft/how-much-ram), [JVM Flags](/docs/minecraft/jvm-flags) | See also: [Types of Server Lag](/docs/minecraft/types-of-server-lag). Crashes and World Corruption [#crashes-and-world-corruption] | Issue | Where to look | Fix | | --------------------------- | ---------------------------------- | ------------------------------------------------------------------------- | | Server crashed | `crash-reports/` folder | [Find / Read Crash Reports](/docs/minecraft/find-read-crash-reports) | | Crash on world load | Crash report mentions world/entity | [Fix Ticking Entity](/docs/minecraft/fix-ticking-entity) | | Corrupted chunks | World data | Restore from **Backups**, or [Reset Chunks](/docs/minecraft/reset-chunks) | | `level.dat` errors | World folder | Replace with `level.dat_old`, restore backup | | Need to read what crashed | `logs/latest.log` | [Find / Share Server Logs](/docs/minecraft/find-share-server-logs) | | Need to share logs for help | mclo.gs | [Find / Share Server Logs](/docs/minecraft/find-share-server-logs) | Config File Errors [#config-file-errors] | File type | Issue | Fix | | ------------------- | ------------------------------------------ | -------------------------------------------------------------- | | YAML (`.yml`) | "Invalid configuration" / "could not load" | [Find / Fix YAML Errors](/docs/minecraft/find-fix-yaml-errors) | | JSON (`.json`) | "Failed to parse" / "unexpected token" | [Find / Fix JSON Errors](/docs/minecraft/find-fix-json-errors) | | `server.properties` | "Failed to load" | Check for stray characters, save as plain text | | `eula.txt` | EULA not accepted | [Accept the EULA](/docs/minecraft/agree-to-eula) | Plugins and Mods [#plugins-and-mods] | Issue | Fix | | ------------------------------------ | ----------------------------------------------------------------------------------------------- | | Plugin won't load | Check Console for the error, see [Find / Fix YAML Errors](/docs/minecraft/find-fix-yaml-errors) | | Mod won't load | Check Java/MC version compatibility, see [Mod Setup](/docs/minecraft/mod-setup) | | Forge mods + Bukkit plugins together | Use a hybrid JAR — see [Install Custom JAR](/docs/minecraft/install-custom-jar) | | Plugin causes server lag | [Setup Spark](/docs/minecraft/setup-spark) → identify, then update or remove | | Plugin requires a database | [Use MySQL Database](/docs/minecraft/use-mysql-database) | BungeeCord / Velocity Networks [#bungeecord--velocity-networks] | Issue | Fix | | ------------------------------------- | ------------------------------------------------------------------------ | | Setting up a network | [BungeeCord Setup](/docs/minecraft/bungeecord-guide) | | IP forwarding broken | [BungeeCord IP Forwarding](/docs/minecraft/bungeecord-ip-forwarding) | | `If you wish to use IP forwarding...` | [BungeeCord Troubleshooting](/docs/minecraft/bungeecord-troubleshooting) | | Backend not reachable from proxy | [BungeeCord Troubleshooting](/docs/minecraft/bungeecord-troubleshooting) | The Universal First Step [#the-universal-first-step] **Read the Console.** Almost every problem on a Minecraft server is logged in **Console** in the [XGamingServer Panel](https://panel.xgamingserver.com). Read the **first** error message — later ones are usually side effects. If you can't make sense of it, share the log via [mclo.gs](https://mclo.gs/) and ask in our [Discord](https://discord.xgamingserver.com/). Related Guides [#related-guides] * [Server Won't Start](/docs/minecraft/fix-server-wont-start) * [Optimize Server](/docs/minecraft/optimize-server) * [Setup Spark](/docs/minecraft/setup-spark) * [Find / Read Crash Reports](/docs/minecraft/find-read-crash-reports) * [Find / Share Server Logs](/docs/minecraft/find-share-server-logs) * [Java Exit Codes](/docs/minecraft/fix-java-exit-codes)