The problem
A step-by-step method to find why modded Minecraft crashes while launching or loading, and how to fix it without guessing.
Possible causes
- A mod that does not support your Minecraft version or loader.
- A missing or outdated dependency.
- Two mods that cannot run together.
- The wrong Java version.
How to identify the cause
- Find the crash report in
crash-reportsinside the instance folder. Read the Description line and the first block of the stack trace. - Look for a "Suspected Mods" section. Forge, NeoForge and Fabric often list the mod that caused the crash.
- If there is no crash report, read
logs/latest.logfrom the bottom up until you find the first error.
Step-by-step fix
- Note the suspected mod and check its page for your Minecraft version and loader.
- Update the mod, or remove it if it does not support your setup.
- Install any missing dependency the log names.
- Remove recently added mods one at a time if you changed several things at once.
- Check your Java version against the Minecraft version.
- Launch again and repeat until the game reaches the title screen.
If that did not work
- Binary search: remove half of the mods, test, and keep halving the group that crashes. With 200 mods this finds the cause in about eight launches.
- Ask for help with the full log pasted to a log-sharing site such as mclo.gs, not a screenshot.
Affected versions
All Minecraft versions, Java Edition.
Frequently asked questions
Where is my instance folder?
In the official launcher it is .minecraft (on Windows, %appdata%\.minecraft). Other launchers have an "Open folder" button on each instance.
Should I delete my mods folder?
No. Move mods out instead, so you can put them back once you find the problem.