ClassNotFoundException: SpongeCoremod


Hello there,

I am new to Sponge and I have a problem to start the server in Eclipse.

I’ve done all steps from here: and from here:

Now I tried to start the server within Eclipse but I’ve got following output

[05:31:28] [main/INFO] [GradleStart]: Extra: []
[05:31:28] [main/INFO] [GradleStart]: Running with arguments: [--tweakClass, net.minecraftforge.fml.common.launcher.FMLServerTweaker, --tweakClass, net.minecraftforge.gradle.tweakers.CoremodTweaker]
[05:31:28] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLServerTweaker
[05:31:28] [main/INFO] [LaunchWrapper]: Using primary tweak class name net.minecraftforge.fml.common.launcher.FMLServerTweaker
[05:31:28] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.gradle.tweakers.CoremodTweaker
[05:31:28] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLServerTweaker
2019-03-04 05:31:29,766 main WARN Disabling terminal, you're running in an unsupported environment.
[05:31:29] [main/INFO] [FML]: Forge Mod Loader version for Minecraft 1.12.2 loading
[05:31:29] [main/INFO] [FML]: Java is Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_201, running on Windows 10:amd64:10.0, installed at C:\Program Files\Java\jdk1.8.0_201\jre
[05:31:29] [main/ERROR] [FML]: Apache Maven library folder was not in the format expected. Using default libraries directory.
[05:31:29] [main/ERROR] [FML]: Full: C:\Users\Xearox\.gradle\caches\modules-2\files-2.1\org.apache.maven\maven-artifact\3.5.3\7dc72b6d6d8a6dced3d294ed54c2cc3515ade9f4\maven-artifact-3.5.3.jar
[05:31:29] [main/ERROR] [FML]: Trimmed: c:/users/xearox/.gradle/caches/modules-2/files-2.1/org.apache.maven/maven-artifact/3.5.3/
[05:31:30] [main/INFO] [FML]: Managed to load a deobfuscated Minecraft name- we are in a deobfuscated environment. Skipping runtime deobfuscation
[05:31:30] [main/INFO] [FML]: Ignoring missing certificate for coremod FMLCorePlugin (net.minecraftforge.fml.relauncher.FMLCorePlugin), we are in deobf and it's a forge core plugin
[05:31:30] [main/INFO] [FML]: Ignoring missing certificate for coremod FMLForgePlugin (net.minecraftforge.classloading.FMLForgePlugin), we are in deobf and it's a forge core plugin
[05:31:30] [main/INFO] [FML]: Found a command line coremod : org.spongepowered.mod.SpongeCoremod
[05:31:30] [main/ERROR] [FML]: Coremod org.spongepowered.mod.SpongeCoremod: Unable to class load the plugin java.lang.ClassNotFoundException: org.spongepowered.mod.SpongeCoremod
[05:31:30] [main/INFO] [FML]: Searching C:\dev\minecraft\spongegit\SpongeForge\run\.\mods for mods
[05:31:30] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.gradle.tweakers.CoremodTweaker

These are the JVM arguments


So … I don’t now to do next.

Thank you for your help

Is there something what I am missing here? I’ve already read this: /t/unable-to-class-load-the-plugin-java-lang-classnotfoundexception-org-spongepowered-mod-spongecoremod/25913/6

And there is an other forum posting but this one is in French and I am not familar with French :wink:


I’ve done all steps again and I want to share you the results after all…

This is the result after I’ve run ./gradlew and ./gradlew eclipse

Oh and before I forgot. … Look at testmods. Duplicate entries … And not just this one. There are a lot of duplicated entries.

If I now starting the server, without any plugins

The SpongeCoreMod is still missing. Yes, I know I haven’t accepted the EULA, because it’s a fresh “install”.

After all … I don’t know what to do now. Maybe I am really missing something. Oh and … I don’t want to switch the IDE. I am working with Eclipse since 11 years and I am not new to Java :wink:

Edit: After removing all duplicated entries the CoreMod can be found now but … A lot of errors :wink: