SerializationComponentRegistrar is not compatible with this version of compiler - kotlin

Question

I am getting this error inside AS - even though I tripple checked to pick a valid version pairing (kotlin 1.2.40 with serialisation 0.5.0):
Error:Kotlin: [Internal Error] java.lang.IllegalStateException: The provided plugin org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationComponentRegistrar is not compatible with this version of compiler
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment.<init>(KotlinCoreEnvironment.kt:186)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment.<init>(KotlinCoreEnvironment.kt:119)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment$Companion.createForProduction(KotlinCoreEnvironment.kt:418)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.createCoreEnvironment(K2JVMCompiler.kt:265)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:154)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:63)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:107)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:51)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:96)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$$inlined$ifAlive$lambda$1.invoke(CompileServiceImpl.kt:399)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$$inlined$ifAlive$lambda$1.invoke(CompileServiceImpl.kt:98)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:920)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:98)
at org.jetbrains.kotlin.daemon.common.DummyProfiler.withMeasure(PerfUtils.kt:137)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.checkedCompile(CompileServiceImpl.kt:950)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.doCompile(CompileServiceImpl.kt:919)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:397)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:361)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.AbstractMethodError: org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationComponentRegistrar.registerProjectComponents(Lcom/intellij/mock/MockProject;Lorg/jetbrains/kotlin/config/CompilerConfiguration;)V
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment.<init>(KotlinCoreEnvironment.kt:184)
... 33 more

Answer 1

Check your installed Kotlin plugin in the idea(Tools>Kotlin>Configure Kotlin Plugin Updates). Must be same as in your build.gradle file.

Answer 2

There's an IntelliJ / Android Studio plugin that's made just for the Kotlin Serialization support, separate from the main Kotlin plugin. From the Working in IntelliJ IDEA section of the readme:
Because serialization is still highly experimental, it is shipped as a separate artifact from "big" Kotlin IDEA plugin. You can download additional IDEA plugin for working with projects that uses serialization from its TeamCity build page
It provides links to the latest TeamCity builds for this plugin, including this one for Kotlin 1.2.40.
Since they only currently publish this plugin through TeamCity, you would have to install it manually by going to Preferences > Plugins > Install plugin from disk...
For anyone using IntelliJ instead of Android Studio, if the plugin doesn't solve the problem, the same readme says to:
try to use gradle for running builds: Settings - Build, Execution, Deployment - Build Tools - Gradle - Runner - tick Delegate IDE build/run actions to gradle; or launch builds from console.
There's an open ticket on Github about this error message, and it might also be worth keeping an eye on that.