Kotlin serialization not working on JS

[ollesate]

I'm trying to get serialization to work in my game to support sending messages between client and server

Its not compiling on javascript.

I tried doing the same thing on a kotlin js browser project and it worked fine so I'm thinking this is something with Korge.

Minimal project based on hello world project:
https://github.com/korlibs/korge-hello-world/compare/master...ollesate:os_serialization?expand=1

To test:
./gradlew compileKotlinJs

e: java.util.NoSuchElementException: Collection contains no element matching the predicate.
        at org.jetbrains.kotlinx.serialization.compiler.backend.ir.IrBuilderExtension$DefaultImpls.createLazyProperty(GeneratorHelpers.kt:1413)
        at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializableCompanionIrGenerator.createLazyProperty(SerializableCompanionIrGenerator.kt:29)
        at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializableCompanionIrGenerator.generateLazySerializerGetter(SerializableCompanionIrGenerator.kt:108)
        at org.jetbrains.kotlinx.serialization.compiler.backend.common.SerializableCompanionCodegen.generate(SerializableCompanionCodegen.kt:37)
        at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializableCompanionIrGenerator$Companion.generate(SerializableCompanionIrGenerator.kt:44)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializerClassLowering.lower(SerializationLoweringExtension.kt:60)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:36)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitClass(IrElementVisitorVoid.kt:44)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:55)
        at org.jetbrains.kotlin.ir.declarations.IrClass.acceptChildren(IrClass.kt:60)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoidKt.acceptChildrenVoid(IrElementVisitorVoid.kt:275)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:37)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitClass(IrElementVisitorVoid.kt:44)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:55)
        at org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl.acceptChildren(IrFileImpl.kt:84)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoidKt.acceptChildrenVoid(IrElementVisitorVoid.kt:275)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitElement(SerializationLoweringExtension.kt:32)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitPackageFragment(IrElementVisitorVoid.kt:30)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitPackageFragment(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitFile(IrElementVisitorVoid.kt:37)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitFile(IrElementVisitorVoid.kt:38)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl.accept(IrFileImpl.kt:81)
        at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoidKt.acceptVoid(IrElementVisitorVoid.kt:271)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt.runOnFileInOrder(SerializationLoweringExtension.kt:30)
        at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtension.generate(SerializationLoweringExtension.kt:77)
        at org.jetbrains.kotlin.ir.backend.js.KlibKt.generateModuleFragmentWithPlugins$lambda-20(klib.kt:402)
        at org.jetbrains.kotlin.psi2ir.Psi2IrTranslator.generateModuleFragment(Psi2IrTranslator.kt:89)
        at org.jetbrains.kotlin.ir.backend.js.KlibKt.generateModuleFragmentWithPlugins(klib.kt:407)