Minecraft crash log analyzer: paste your log, get the fix
Works with Forge, NeoForge, Fabric and Quilt. Drop in a crash report or latest.log and we'll tell you what broke and how to fix it, in plain English. Free, and no sign-up.
Where to find your crash log
The analyzer reads two kinds of file. A crash report is written when the game or server crashes outright. latest.log is the running log of the current session; use it when the server stopped, froze or never finished starting without writing a crash report.
| Where it ran | Crash reports | Log |
|---|---|---|
| A server on your own PC | crash-reports/ in the server folder | logs/latest.log |
| A hosted server | The same folders, in the panel's file manager | logs/latest.log, or copy the console output |
| The game, Windows | %APPDATA%\.minecraft\crash-reports\ | %APPDATA%\.minecraft\logs\latest.log |
| The game, macOS | ~/Library/Application Support/minecraft/crash-reports/ | …/minecraft/logs/latest.log |
| The game, Linux | ~/.minecraft/crash-reports/ | ~/.minecraft/logs/latest.log |
| CurseForge, Prism Launcher, Modrinth App | Each instance has its own folder: open it from the launcher, then crash-reports/ | logs/latest.log in that folder |
- Crash reports are named by date and time, like
crash-2026-10-12_14.03.55-server.txt. Take the newest one. A crash on a player's PC ends in-client.txt. - If the server restarted after crashing,
latest.lognow belongs to the new run. Earlier runs are kept inlogs/as dated.log.gzfiles; unzip the newest and paste that. - Forge and NeoForge also write
logs/debug.log, with more detail. Iflatest.logshows no cause, try that. - The upload limit is 2 MB. For a bigger log, paste the crash report on its own, or the last few thousand lines, where the error is.
What the analyzer recognizes
Our own rules match these crashes instantly, from the lines they leave in a log, and name the mod involved when the log does. Each one has a full guide.
- Wrong Java version
UnsupportedClassVersionErroror “class file version 65.0”: the server is running a different Java than its Minecraft version needs. Our Java version chart lists the right one. - Out of memory
java.lang.OutOfMemoryError: Java heap space, plus the Metaspace and native-thread versions. See also how much RAM your server needs. - Missing mod dependencyA mod that needs another mod, or a newer version of one, that isn't installed.
- Client-only mod on a server“invalid dist DEDICATED_SERVER” and missing
net.minecraft.clientclasses. Checking a whole mods folder? Use the client-or-server-side checker. - Mixin errors“Mixin apply failed” and
InvalidInjectionException: two mods changing the same code, or a mod that doesn't match the game version. - Duplicate modsThe same mod installed twice, often two versions side by side.
- Wrong mod loader or Minecraft versionA Fabric mod on a Forge server, a mod built for another Minecraft version, or a loader that's too old.
- Failed to bind to port
**** FAILED TO BIND TO PORT!: something else, often a second copy of the server, already uses the port. - EULA not accepted“You need to agree to the EULA in order to run the server.”
- Watchdog: server froze“A single server tick took 60.00 seconds”: one tick ran so long the server shut itself down.
- Corrupt chunk or world“Couldn't load chunk” and damaged region files.
Guides for problems the rules don't name yet
These have full guides, but the analyzer doesn't match them by rule yet. A log with no known cause gets the AI read described below, which may still explain them.
- Friends can't join“Mismatched mod channel list”, mod rejections and connection errors. These usually show on the player's screen, not in the server log.
- “Can't keep up! Is the server overloaded?”Lag rather than a crash: how to read TPS and MSPT and find what's slowing the server down.
- Exception ticking entity or block entityA crash loop caused by one broken mob, item or machine, and how to remove it safely.
What happens to your log
- Your log is sent to our server, analyzed in memory and not stored.
- Before any part of it is sent for an AI read or shown back to you, we remove IPv4 addresses, the username in home-folder paths (the
yournameinC:\Users\yourname) and values that look like access tokens, session tokens or passwords. Player names, world names and mod names stay as they are, so check the log before you paste it if that matters to you. - Our own rules run first, on Cloudflare's network. Only when they can't explain the crash, or you ask for a deeper read, is a trimmed excerpt of the redacted log (the key error lines and the end of the log) sent to Anthropic's API to write the diagnosis. Under Anthropic's commercial terms it isn't used to train their models.
- To keep the AI read free, your IP address is used to count AI reads per hour. That counter deletes itself after about an hour.
- If you paste an mclo.gs link, our server fetches that log from mclo.gs's public API (it's already public there) and handles it like a pasted log, so mclo.gs sees our server, not your IP address. To stop abuse, those fetches are counted per IP address per hour, in memory only, and the count is dropped when the hour ends.
- A result link (“Copy link to this result”) holds only which known problems were found and the Minecraft, loader and Java versions. No line of the log, mod name or AI text goes in it.
The full details are in our privacy policy.
Common questions
What's the difference between a crash report and latest.log?
A crash report is a summary Minecraft writes at the moment of a crash: the error, the stack trace and, on modded servers, often a list of suspected mods. latest.log is everything the server printed while it ran. Paste the crash report if there is one; if the server stopped or froze without one, paste latest.log.
Which crashes can it fix?
Instant answers for the most common ones: wrong Java version, out of memory, missing dependency mods, client-only mods on a server, duplicate mods, mods made for another loader or Minecraft version, mixin conflicts, port conflicts, an EULA that hasn't been accepted, watchdog freezes and damaged world or chunk data. Anything else gets a deeper AI read of the stack trace.
Does it work for crashes on my own PC, not just servers?
Yes. It reads crash reports and logs from the game as well as from servers, and shows which kind it's looking at. Most rules are written for server crashes, so a crash caused by graphics drivers or shaders on a PC is more likely to get only the AI read.
It says “No known cause found”. What now?
Find the first line that starts with Caused by: and look for a mod name in the lines under it. That mod, or one it depends on, is usually the problem. On Forge and NeoForge, debug.log often says more than latest.log. Still stuck? Email the log to hello@dsnservers.com.
Is it really free?
Yes. No account and no email needed. The instant answers are unlimited. The deeper AI read has an hourly limit per visitor and a daily limit for everyone together, so the tool can stay free.
Can I paste an mclo.gs link?
Yes. Paste the link on its own, like https://mclo.gs/AbC1234, and press Find the fix. We fetch the log from mclo.gs and read it like a pasted one. For a very long log we keep the start and the end, which is where errors show up.
Can I share the result with my server?
Yes. Under a result with known problems, press Copy link to this result and post the link in your server's Discord or support thread. It opens the same diagnosis and fixes in general terms: the link holds only which problems were found and the Minecraft, loader and Java versions, so nothing from your log is shared, mod names included. An AI read isn't part of the link.
Does it work if my server isn't hosted with you?
Yes. It only needs the log text, so it works wherever your server runs, including your own PC. If you're setting one up yourself, our guide on how to make a modded Minecraft server covers the usual first-start problems.