Couldn't find route for 'frontend/sub-window/icons/baseline-close-24px.svg'

[mailtokarthik2003]

tp-nio-8085-exec-5] ERROR com.vaadin.flow.server.DefaultErrorHandler -
java.lang.RuntimeException: java.lang.IllegalArgumentException: The given component (com.example.test.SubWindow@231538e7) is not a child of this component
at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:210)
at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:181)
at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:139)
at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.handleNode(PublishedServerEventHandlerRpcHandler.java:127)
at com.vaadin.flow.server.communication.rpc.AbstractRpcInvocationHandler.handle(AbstractRpcInvocationHandler.java:66)
at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocationData(ServerRpcHandler.java:438)
at com.vaadin.flow.server.communication.ServerRpcHandler.lambda$handleInvocations$1(ServerRpcHandler.java:419)
at java.util.ArrayList.forEach(Unknown Source)
at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:419)
at com.vaadin.flow.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:320)
at com.vaadin.flow.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:92)
at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1578)
at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:252)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1707)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)

not setting top icons and close button click error i got....