Server Troubleshooting & Crashes
32 guidesA server that will not start, crashes on load, shows online but rejects players, or dies part way through startup.
Almost every crash is answered by the log, so start there rather than with a symptom search. Finding the crash report or logs folder takes a moment, and sending it to us is the quickest route to an answer if you would rather not read it yourself.
If the server will not start at all, the usual causes are a mod or plugin that does not match the server version, a bad startup flag, or a file left behind by a previous install. This guide walks the whole sequence, and this one narrows down which mod is responsible when the log points at a conflict rather than a single culprit.
- "Detected server process in a crashed state" / won't turn on — how do I fix it?
- "op command does not exist" / commands don't work — why?
- A Nether/End portal does nothing ("dimension does not exist") — how do I fix it?
- Are the red startup lines / warnings normal?
- Broken blocks don't drop / blocks regenerate / actions don't register — is this lag?
- Can I recover or reactivate a deleted or long-unpaid server with its data?
- FastLogin / SkinRestorer / /premium command isn't working — how do I fix it?
- How do I fully remove a mod without leaving broken data or crashing?
- How do I send a crash report / latest.log for help?
- How do I set up and manage a whitelist?
- How was my server accessed without authorization / can you find who?
- I get a timeout or get kicked a few seconds after joining — what causes it?
- I spawn in the void / free-fall and get kicked when joining — how do I fix it?
- Is my current plan enough, or will it lag/crash with my setup?
- Joining kicks another player / only one player can be online at a time — why?
- Mobs aren't spawning or spawn wrong — how do I fix it?
- My hybrid server is unstable / crashes with version mismatches — help?
- My server crashed right after I added a mod or plugin — how do I identify and fix it?
- My server crashes when generating a structure or entering an area — how do I fix it?
- My server may have malware or was hacked — can you scan/clean it, and keep my data?
- My server restarts with OutOfMemory every few hours — how do I fix it?
- My server takes very long to stop / is stuck "stopping" for minutes — why?
- My server won't start or keeps crashing — what do I do?
- Players in certain countries get very high ping (2000ms+) — how do I fix it?
- Ranks/permissions are lost on relogin or death — how do I fix it?
- Respawn is broken (respawn at spawn, spectator on death) — how do I fix it?
- Server shows Online but nobody can join — why?
- The Versions tab won't load or says it can't install — how do I fix it?
- The server shows offline when I start it, or stuck starting at a % for hours — what's wrong?
- What do specific warnings mean (maxHealth, "moved too quickly," GC spam, chat validation)?
- Where do I find the crash report or logs folder?
- Which mod is causing my crash, and how do I find it?
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