`MissingKotlinParameterException` wraped by `DecodingException`

Hi, everybody!

Why MissingKotlinParameterException wrapped by DecodingException and uncatchable in ControllerAdvice?

In the following, there is the complete response :
{
“timestamp”: “2020-07-25T10:35:39.165+00:00”,
“path”: “/boarding/subscribeUserWithSoloWorkspace”,
“status”: 400,
“error”: “Bad Request”,
“message”: “Request body is missing: public reactor.core.publisher.Mono<org.springframework.http.ResponseEntity<?>> co.ashiyane.flare.controllers.BoardingController.subscribeUserWithSoloWorkspace(co.ashiyane.flare.domains.supdomains.UserAndWorkspace)”,
“requestId”: “6d4ec654-2”,
“trace”: “org.springframework.web.server.ServerWebInputException: 400 BAD_REQUEST “Request body is missing: public reactor.core.publisher.Mono<org.springframework.http.ResponseEntity<?>> co.ashiyane.flare.controllers.BoardingController.subscribeUserWithSoloWorkspace(co.ashiyane.flare.domains.supdomains.UserAndWorkspace)”\n\tat org.springframework.web.reactive.result.method.annotation.AbstractMessageReaderArgumentResolver.handleMissingBody(AbstractMessageReaderArgumentResolver.java:230)\n\tSuppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: \nError has been observed at the following site(s):\n\t|_ checkpoint ⇢ org.springframework.web.filter.reactive.ServerWebExchangeContextFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ co.ashiyane.flare.security.LoggingWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.authorization.AuthorizationWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.authorization.ExceptionTranslationWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.authentication.logout.LogoutWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.savedrequest.ServerRequestCacheWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.context.SecurityContextServerWebExchangeWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.authentication.AuthenticationWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.context.ReactorContextWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.header.HttpHeaderWriterWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.config.web.server.ServerHttpSecurity$ServerWebExchangeReactorContextWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.security.web.server.WebFilterChainProxy [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]\n\t|_ checkpoint ⇢ HTTP POST “/boarding/subscribeUserWithSoloWorkspace” [ExceptionHandlingWebHandler]\nStack trace:\n\t\tat org.springframework.web.reactive.result.method.annotation.AbstractMessageReaderArgumentResolver.handleMissingBody(AbstractMessageReaderArgumentResolver.java:230)\n\t\tat org.springframework.web.reactive.result.method.annotation.AbstractMessageReaderArgumentResolver.lambda$readBody$8(AbstractMessageReaderArgumentResolver.java:215)\n\t\tat reactor.core.publisher.MonoErrorSupplied.subscribe(MonoErrorSupplied.java:70)\n\t\tat reactor.core.publisher.Mono.subscribe(Mono.java:4219)\n\t\tat reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75)\n\t\tat reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)\n\t\tat reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)\n\t\tat reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)\n\t\tat reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)\n\t\tat reactor.core.publisher.Operators.complete(Operators.java:135)\n\t\tat reactor.netty.channel.FluxReceive.startReceiver(FluxReceive.java:294)\n\t\tat reactor.netty.channel.FluxReceive.lambda$subscribe$2(FluxReceive.java:138)\n\t\tat io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)\n\t\tat io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)\n\t\tat io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:384)\n\t\tat io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)\n\t\tat io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)\n\t\tat io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)\n\t\tat java.base/java.lang.Thread.run(Thread.java:832)\n”
}