Проблема с компиляцией приложения GWT - Ошибка, статус 503

Я новичок в ГВТ. Я уже создал первые приложения, которые работали, и я застрял на другом - я не могу запустить. У меня в браузере статус 503

Я что-то забыл?

Все в разделе модуля в настройках проекта так же, как и в других приложениях, pom.xml все равно может быть, я должен внести некоторые изменения в web.xml? Найдя несколько решений подобной проблемы, я удалил в файле web.xml следующие строки:

<servlet>
    <servlet-name>greetServlet</servlet-name>
    <servlet-class>eu.mrndesign.matned.server.GreetingServiceImpl</servlet-class>
  </servlet>
  
  <servlet-mapping>
    <servlet-name>greetServlet</servlet-name>
    <url-pattern>/arkanoidgame/greet</url-pattern>
  </servlet-mapping>

вот трассировка стека:

 > Starting Jetty on port 8888
   [WARN] Failed startup of context c.g.g.d.s.j.WebAppContextWithReload@3027a1f1{/,file:/C:/Users/matni/.IntelliJIdea2019.3/system/gwt/arkanoidgame.b9d5fc4/ArkanoidGame.513aa147/run/www/,STARTING}{C:\Users\matni\.IntelliJIdea2019.3\system\gwt\arkanoidgame.b9d5fc4\ArkanoidGame.513aa147\run\www}
MultiException[java.lang.RuntimeException: Error scanning file ArkanoidGame$1.class, java.lang.RuntimeException: Error scanning file ArkanoidGame$1MyHandler$1.class, java.lang.RuntimeException: Error scanning file ArkanoidGame$1MyHandler.class, java.lang.RuntimeException: Error scanning file ArkanoidGame.class]
    at org.eclipse.jetty.annotations.AnnotationConfiguration.scanForAnnotations(AnnotationConfiguration.java:536)
    at org.eclipse.jetty.annotations.AnnotationConfiguration.configure(AnnotationConfiguration.java:447)
    at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:479)
    at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1337)
    at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:741)
    at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:505)
    at com.google.gwt.dev.shell.jetty.JettyLauncher$WebAppContextWithReload.doStart(JettyLauncher.java:550)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
    at org.eclipse.jetty.server.handler.RequestLogHandler.doStart(RequestLogHandler.java:140)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.server.Server.start(Server.java:387)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
    at org.eclipse.jetty.server.Server.doStart(Server.java:354)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:760)
    at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:636)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:898)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:705)
    at com.google.gwt.dev.DevMode.main(DevMode.java:432)
Caused by: MultiException[java.lang.RuntimeException: Error scanning file ArkanoidGame$1.class, java.lang.RuntimeException: Error scanning file ArkanoidGame$1MyHandler$1.class, java.lang.RuntimeException: Error scanning file ArkanoidGame$1MyHandler.class, java.lang.RuntimeException: Error scanning file ArkanoidGame.class]
    at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:681)
    at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
    at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
    at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
    at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
    at org.eclipse.jetty.annotations.AnnotationParser.parse(AnnotationParser.java:824)
    at org.eclipse.jetty.annotations.AnnotationConfiguration$ParserTask.call(AnnotationConfiguration.java:163)
    at org.eclipse.jetty.annotations.AnnotationConfiguration$1.run(AnnotationConfiguration.java:548)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
    at java.base/java.lang.Thread.run(Thread.java:834)
    Suppressed: java.lang.RuntimeException: Error scanning file ArkanoidGame$1MyHandler$1.class
        at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:708)
        ... 10 more
    Caused by: java.lang.UnsupportedOperationException: This feature requires ASM7
        at org.objectweb.asm.ClassVisitor.visitNestHost(ClassVisitor.java:150)
        at org.objectweb.asm.ClassReader.accept(ClassReader.java:550)
        at org.objectweb.asm.ClassReader.accept(ClassReader.java:400)
        at org.eclipse.jetty.annotations.AnnotationParser.scanClass(AnnotationParser.java:974)
        at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:702)
        ... 10 more
    Suppressed: java.lang.RuntimeException: Error scanning file ArkanoidGame$1MyHandler.class
        at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:708)
        ... 10 more
    Caused by: java.lang.UnsupportedOperationException: This feature requires ASM7
        at org.objectweb.asm.ClassVisitor.visitNestHost(ClassVisitor.java:150)
        at org.objectweb.asm.ClassReader.accept(ClassReader.java:550)
        at org.objectweb.asm.ClassReader.accept(ClassReader.java:400)
        at org.eclipse.jetty.annotations.AnnotationParser.scanClass(AnnotationParser.java:974)
        at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:702)
        ... 10 more
    Suppressed: java.lang.RuntimeException: Error scanning file ArkanoidGame.class
        at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:708)
        ... 10 more
    Caused by: java.lang.UnsupportedOperationException: This feature requires ASM7
        at org.objectweb.asm.ClassVisitor.visitNestMember(ClassVisitor.java:236)
        at org.objectweb.asm.ClassReader.accept(ClassReader.java:660)
        at org.objectweb.asm.ClassReader.accept(ClassReader.java:400)
        at org.eclipse.jetty.annotations.AnnotationParser.scanClass(AnnotationParser.java:974)
        at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:702)
        ... 10 more
Caused by: java.lang.RuntimeException: Error scanning file ArkanoidGame$1.class
    at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:708)
    ... 10 more
Caused by: java.lang.UnsupportedOperationException: This feature requires ASM7
    at org.objectweb.asm.ClassVisitor.visitNestHost(ClassVisitor.java:150)
    at org.objectweb.asm.ClassReader.accept(ClassReader.java:550)
    at org.objectweb.asm.ClassReader.accept(ClassReader.java:400)
    at org.eclipse.jetty.annotations.AnnotationParser.scanClass(AnnotationParser.java:974)
    at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:702)
    ... 10 more
2020-12-13 10:41:02.813:INFO:oejs.ServerConnector:main: Started ServerConnector@2f067ac5{HTTP/1.1}{127.0.0.1:8888}
2020-12-13 10:41:02.815:INFO:oejs.Server:main: Started @18361ms
Dev Mode initialized. Startup URL: 
http://127.0.0.1:8888/ArkanoidGame.html
[ERROR] 503 - GET /ArkanoidGame.html (127.0.0.1) 305 bytes
   Request headers
      Host: 127.0.0.1:8888
      Connection: keep-alive
      DNT: 1
      Upgrade-Insecure-Requests: 1
      User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36
      Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
      Sec-Fetch-Site: none
      Sec-Fetch-Mode: navigate
      Sec-Fetch-User: ?1
      Sec-Fetch-Dest: document
      Accept-Encoding: gzip, deflate, br
      Accept-Language: pl-PL,pl;q=0.9,en-US;q=0.8,en;q=0.7
   Response headers
      Date: Sun, 13 Dec 2020 09:41:03 GMT
      Cache-Control: must-revalidate,no-cache,no-store
      Content-Type: text/html; charset=ISO-8859-1
      Content-Length: 305