I have a brand new install of Intellij 2020.3.3 Community and JDK v16. I booted up Intellij, and made sure to update the Kotlin plugin. I created a new Kotlin project, and have made no changes to it. I attempted to run the Kotlin REPL tool (Tools->Kotlin->Kotlin REPL) and I get the following exception:
"C:\Program Files\Java\jdk-16\bin\java.exe" -Dkotlin.repl.ideMode=true -Dfile.encoding=UTF-8 @C:\Users\---\AppData\Local\Temp\idea_arg_file349852720
exception: java.lang.ExceptionInInitializerError
at com.intellij.pom.java.LanguageLevel.<clinit>(LanguageLevel.java:25)
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$ProjectEnvironment.<init> (KotlinCoreEnvironment.kt:121)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:90)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:52)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:88)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:44)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:98)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:76)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:45)
at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMainNoExit(CLITool.kt:227)
at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMainNoExit$default(CLITool.kt:222)
at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMain(CLITool.kt:214)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler$Companion.main(K2JVMCompiler.kt:271)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.main(K2JVMCompiler.kt)
Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected void java.util.ResourceBundle.setParent(java.util.ResourceBundle) accessible: module java.base does not "opens java.util" to unnamed module @55141def
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:357)
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199)
at java.base/java.lang.reflect.Method.setAccessible(Method.java:193)
at com.intellij.util.ReflectionUtil.makeAccessible(ReflectionUtil.java:252)
at com.intellij.util.ReflectionUtil.getDeclaredMethod(ReflectionUtil.java:269)
at com.intellij.DynamicBundle.<clinit>(DynamicBundle.java:22)
... 17 more
I have attempted to reinstall the JDK/IDE, and cleared the temp folder. Not sure what else to try, both the IDE and language are new to me. Suggestions?
EDIT
Found workaround: I did another uninstall, and downgraded to JDKv8 and the issue isn't present.