Is this a compiler error with generics?

Given the following base classes:

package com.cartrawler.shopdirect.domain

import com.github.benmanes.caffeine.cache.Cache
import java.io.Serializable



interface Event<out T : Serializable> : Serializable {
    val userId: String
    val data: T
}

private data class EventTemplate<out T : Serializable>(override val userId: String, override val data: T) : Event<T>, Serializable

interface EventListener<in T : Event<Serializable>> {
    fun onEvent(event: T)
}


class PreferenceChangeEvent(userId: String, preference: Preference)
    : Event<Preference> by EventTemplate(userId, preference)

class ExecuteRequestStartedEvent(userId: String, msg: String)
    : Event<String> by EventTemplate(userId, msg)

data class ExecuteRequestPayload(val userId: String, val serverUrl: String, val request: Request) : Serializable
class ExecuteRequestError(userId: String, throwable: Throwable)
    : Event<Throwable> by EventTemplate(userId, throwable)

data class ExecuteRequestFinishedPayload(val executeRequestPayload: ExecuteRequestPayload,
                                         val parseResult: ParseResult) : Serializable

class ExecuteRequestFinishedEvent(userId: String, payload: ExecuteRequestFinishedPayload)
    : Event<ExecuteRequestFinishedPayload> by EventTemplate(userId, payload)


typealias RequestExecuteCache = Cache<ExecuteRequestPayload, ExecuteRequestFinishedEvent>

interface ExecuteRequestStartedEventListener : EventListener<ExecuteRequestStartedEvent> {
    override fun onEvent(event: ExecuteRequestStartedEvent)
}

interface ExecuteRequestErrorListener : EventListener<ExecuteRequestError> {
    override fun onEvent(event: ExecuteRequestError)
}

interface PreferenceChangeEventListener : EventListener<PreferenceChangeEvent> {
    override fun onEvent(event: PreferenceChangeEvent)
}

Declaring the following does not work:

@UIScope
@SpringComponent
class AppUpdaterEventListener(val user: User) : ExecuteRequestErrorListener, ExecuteRequestStartedEventListener {

The compiler error is: