Error: Runtime exited without providing a reason Runtime.ExitError

I was trying to get this working using Kotlin but I keep getting this: Error: Runtime exited without providing a reason Runtime.ExitError.

My handler is setup like this

class SimpleHandler: RequestHandler {
val logger = LoggerFactory.getLogger(SimpleHandler::class.java)
val jsonMapper = jacksonObjectMapper()
var responseFromClient: String = ""

override fun handleRequest(input: APIGatewayProxyRequestEvent?, context: Context?): APIGatewayProxyResponseEvent {
logger.info("APIGatewayProxyRequestEvent received: \n ${jsonMapper.writeValueAsString(input)}")

}

}

I don't have a main class as the java example. I noticed that when I added a main class I get a different error: Request Timeout but maybe is because is trying to wait for and answer from main execution. Please advice.

Start by comparing the Kotlin SimpleHandler implementation with the repository's Java example and the custom runtime entry point. Reproduce the Runtime.ExitError and the Request Timeout, then confirm that the handler can be invoked without either failure and provides the expected response.

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