Kotlin: [Internal Error] java.lang.NoClassDefFoundError: Could not initialize class com.intellij.pom.java.LanguageLevel

Question

I just wrote

fun main() {
    println("Hello World")
}

on Project\src\HelloWorld.kt But, I came across this error: java.lang.NoClassDefFoundError . I wonder why it doesn't work because I having seen the same print code run.

How do i serve this error? Below is the content of error.

Kotlin: [Internal Error] java.lang.NoClassDefFoundError: Could not initialize class com.intellij.pom.java.LanguageLevel
    at com.intellij.core.CoreLanguageLevelProjectExtension.<init>(CoreLanguageLevelProjectExtension.java:26)
    at com.intellij.core.JavaCoreProjectEnvironment.<init>(JavaCoreProjectEnvironment.java:42)
    at org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreProjectEnvironment.<init>(KotlinCoreProjectEnvironment.kt:26)
    at org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment$ProjectEnvironment.<init>(KotlinCoreEnvironment.kt:121)
    at org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment$Companion.createForProduction(KotlinCoreEnvironment.kt:425)
    at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.createCoreEnvironment(K2JVMCompiler.kt:226)
    at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:152)
    at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:52)
    at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:88)
    at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:44)
    at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:98)
    at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1500)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at java.rmi/sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357)
    at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:200)
    at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:691)
    at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:587)
    at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
    at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:705)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
    at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:704)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
    at java.base/java.lang.Thread.run(Thread.java:831)

Answer 1

If you are using Java 16, it seems be a known issue about it. ref: JDK 16 - e: java.lang.NoClassDefFoundError: Could not initialize class org.jetbrains.kotlin.com.intellij.pom.java.LanguageLevel

Answer 2

要么更新到支持 JDK 16 的 Kotlin 1.5.10+，要么将 JDK 版本降级到您正在使用的 Kotlin 版本支持的版本（尝试 JDK 11）。

Answer 3

I followed the instructions on this issue https://youtrack.jetbrains.com/issue/KT-46604 .

Just hit the update button on IntelliJ and after that the application worked even with JDK 16.

Answer 4

What worked for me

is to use a workaround with illegal access flag

org.gradle.jvmargs=--illegal-access=permit -Dkotlin.daemon.jvm.options=--illegal-access=permit

clear Gradle cache

rm -r $HOME/.gradle/caches/

and after all Gradle daemons killed

pkill -f '.*GradleDaemon.*'

You can try to sync the project and rebuild