v0.9.1 SerializationException: Can't locate argument-less serializer

@Serializable
data class Data(var txt: String)

@UseExperimental(ImplicitReflectionSerializer::class)
fun main() {
    val myData = Data("Blah blah")

    val js = JSON.unquoted.stringify(myData)
    println(js)
}

will throw

Exception in thread "main" kotlinx.serialization.SerializationException: Can't locate argument-less serializer for class MainKt$main$Data. For generic classes, such as lists, please provide serializer explicitly.
	at kotlinx.serialization.PlatformUtilsKt.serializer(PlatformUtils.kt:28)
	at kotlinx.serialization.context.ContextKt.getOrDefault(Context.kt:39)
	at MainKt.main(Main.kt:15)
	at MainKt.main(Main.kt)

I’m on version 0.9.1 which fixed Bug #250. I’m a bit confused now, because it seems like the same Bug is popping up on me now. Did I miss something here?

[sandwwraith]

This issue seems unrelated to 250 and is more likely caused by non-applied plugin or another problems with your project setup

[sandwwraith]

If you have any questions left, feel free to reopen.