Tool
What crashed, and which mod did it?
Paste a crash report or a chunk of latest.log. This pulls out the exception that actually caused the crash from underneath the ones wrapped around it, and takes a guess at which mod's own code threw it.
Nothing is uploaded. This runs in your browser and the text never reaches our server — that is also why this is a paste box, not a file picker.
Frequently asked
Do I have to upload my crash log?
No. The text is parsed in your own browser and never sent anywhere. A crash log can contain a real filesystem path with your username in it, so this is deliberately a paste box handled locally rather than an upload.
Why does it point at a mod that seems unrelated?
The suspect is the first line in the deepest exception's stack trace that is not Minecraft, a loader, or the JVM itself. That is usually the mod whose code actually threw, but a mod can legitimately call into another mod's code, so treat it as a strong lead rather than a confirmed verdict.
It found nothing. What did I paste wrong?
This looks for lines starting with "Caused by:" or "Exception in thread". If you only pasted the short summary at the top of a crash report, go further down to the full stack trace section and paste that instead.
What is a 'Caused by' chain?
When an exception happens while handling an earlier one, Java prints both, wrapped one inside the other. The one at the bottom of the chain is where the failure actually started; the ones above it are the game's own code reporting that the failure happened somewhere inside them.
If the crash names a mod that turns out to be outdated for your Minecraft version, see checking mod compatibility. If it is a fork of a mod you do not recognise, how to tell a real continuation from a clone covers that.
Is this information wrong or missing something? .