I'm getting the error `Caused by: kotlinx.serialization.json.internal.JsonDecodingException: Polymor...

# serialization

[zt]

I'm getting the error Caused by: kotlinx.serialization.json.internal.JsonDecodingException: Polymorphic serializer was not found for missing class discriminator ('null')
I know that the type field in my json data is missing, however I set up a default deserializer for it.

polymorphicDefaultDeserializer(ApiNext.Renderer.ItemSection::class) {
  ApiNext.Renderer.Separator.serializer()
}

This should work, but it throws that error.

ItemSection is a sealed interface
Seperator is just a serializable object that inherits from it