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If you experience an issue and it’s not listed here, please open a new issue and a contributor will help you further.


Could not find tools.jar

If you encounter this error when building, you most likely don’t have the Java Development Kit (JDK) installed. Head over to here to download the oracle JDK. Install it and try again.

Minecraft not loading at all

Note: only applicable if running through Forge and not an IDE.

What .jar are you using in your mods folder? Make sure to use the one that ends with -release (VERSION-release.jar)

Just doesn’t work when using runClient

Don’t use that, try running it through your IDE or building and running forge normally

Crashes before game starts with SpongePowered error

Make sure your workspace is clean and run ./gradlew clean ./gradlew setupDecompWorkspace ./gradlew build

Crashes before game starts with some obscure Java error

Set your application configuration’s JRE in Intellij to a manual path to a downloaded and extracted Oracle Java 8 JRE

Crashes in-game

Please make sure you’re on the latest version of forge before proceeding!

Look for where it crashed and go to the line it crashed at. Make sure you’re not referencing mc.player or when either of those are null, ie have a if (mc.player == null) return; before you reference those.

When using Intellij / Eclipse

Delete your .gradle cache