It's been a long time since I've made a mod, and I'm trying to set up one for 1.18.1 using Eclipse. (Specifically, it's Forge MDK 39.0.66.) Whenever I run the runClient configuration, even with just the basic example mod code with no code changes, I get this error:

Quote

ForgeException in thread "main" java.util.ServiceConfigurationError: cpw.mods.modlauncher.api.ILaunchHandlerService: Unable to load net.minecraftforge.fml.loading.targets.FMLClientLaunchHandler

I've made sure I have JDK 17 installed, my JAVA_HOME environment variable points to it, I've done gradlew clean and refreshed dependencies, re-ran genEclipseRuns, and even re-added the system JRE library to the project build path. Nothing seems to stop this error.

What am I doing wrong and how do I fix it?

Edited February 9, 20223 yr by IceMetalPunk
Solved

13 hours ago, diesieben07 said:

Post the full log.

Sure:

 

Quote

2022-02-08 17:25:50,588 main WARN Advanced terminal features are not available in this environment
[32m[17:25:50] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher running: args [--launchTarget, forgeclientuserdev, --version, MOD_DEV, --assetIndex, 1.18, --assetsDir, C:\Users\iceme\.gradle\caches\forge_gradle\assets, --gameDir, ., --fml.forgeVersion, 39.0.66, --fml.mcVersion, 1.18.1, --fml.forgeGroup, net.minecraftforge, --fml.mcpVersion, 20211210.034407]
[mForge[32m[17:25:50] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher 9.1.0+9.1.0+main.6690ee51 starting: java version 16.0.2 by Oracle Corporation
[mForgeException in thread "main" java.util.ServiceConfigurationError: cpw.mods.modlauncher.api.ILaunchHandlerService: Unable to load net.minecraftforge.fml.loading.targets.FMLClientLaunchHandler
    at java.base/java.util.ServiceLoader.fail(ServiceLoader.java:582)
    at java.base/java.util.ServiceLoader.loadProvider(ServiceLoader.java:854)
    at java.base/java.util.ServiceLoader$LayerLookupIterator.hasNext(ServiceLoader.java:951)
    at java.base/java.util.ServiceLoader$ProviderSpliterator.tryAdvance(ServiceLoader.java:1481)
    at java.base/java.util.Spliterator.forEachRemaining(Spliterator.java:326)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandler.<init>(LaunchServiceHandler.java:40)
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.<init>(Launcher.java:53)
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.main(Launcher.java:77)
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26)
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23)
    at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:149)
Caused by: java.lang.UnsupportedClassVersionError: net/minecraftforge/fml/loading/targets/FMLClientLaunchHandler has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 60.0
    at java.base/java.lang.ClassLoader.defineClass1(Native Method)
    at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1010)
    at [email protected]/cpw.mods.cl.ModuleClassLoader.readerToClass(ModuleClassLoader.java:116)
    at [email protected]/cpw.mods.cl.ModuleClassLoader.lambda$findClass$16(ModuleClassLoader.java:213)
    at [email protected]/cpw.mods.cl.ModuleClassLoader.loadFromModule(ModuleClassLoader.java:223)
    at [email protected]/cpw.mods.cl.ModuleClassLoader.findClass(ModuleClassLoader.java:213)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:631)
    at java.base/java.lang.Class.forName(Class.java:543)
    at java.base/java.util.ServiceLoader.loadProvider(ServiceLoader.java:852)
    ... 14 more

 

5 hours ago, diesieben07 said:

1.18 requires Java 17.

As I said, I have JDK 17 installed and my JAVA_HOME is pointing to it. Specifically, JDK 17.0.2.

7 hours ago, IceMetalPunk said:

java version 16.0.2 by Oracle Corporation

the game starts with java 16

2 minutes ago, Luis_ST said:

the game starts with java 16

🤦‍♂️ So... yeah. Apparently, even though I added System JRE (and deleted and re-added it multiple times) to my project build path, and even though my JAVA_HOME is pointing to the JDK 17.... Eclipse still treated "System JRE" as "the JRE that was bundled deep in the directory structure of this installation of Eclipse" instead of, you know, my actual system's JRE 😑

Thank you for pointing me in the right direction!