I am using Zeppelin 0.8 on hdp 3.0.In ambari Zeppelin is shown as started but when I try to access Zeppelin UI it shows HTTP ERROR 503 Problem accessing /. Reason: Service Unavailable   Powered by Jetty:// 9.4.11.v20180605   Have checked the permissions on Webapps folder it is fine, even cleared the contents of notebook folder and tried again but with no success. Even deleted the service and reinstalled it on another host but no effect Please help @Shelton  Contents of log : MultiException stack 1 of 1 com.google.gson.JsonSyntaxException: duplicate key: colWidth at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.read(MapTypeAdapterFactory.java:191) at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.read(MapTypeAdapterFactory.java:146) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172) at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40) at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:81) at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172) at com.google.gson.Gson.fromJson(Gson.java:791) at com.google.gson.Gson.fromJson(Gson.java:757) at com.google.gson.Gson.fromJson(Gson.java:706) at com.google.gson.Gson.fromJson(Gson.java:678) at org.apache.zeppelin.notebook.Note.fromJson(Note.java:988) at org.apache.zeppelin.notebook.repo.FileSystemNotebookRepo.get(FileSystemNotebookRepo.java:68) at org.apache.zeppelin.notebook.repo.NotebookRepoSync.get(NotebookRepoSync.java:165) at org.apache.zeppelin.notebook.Notebook.loadNoteFromRepo(Notebook.java:505) at org.apache.zeppelin.notebook.Notebook.loadAllNotes(Notebook.java:589) at org.apache.zeppelin.notebook.Notebook.<init>(Notebook.java:123) at org.apache.zeppelin.server.ZeppelinServer.<init>(ZeppelinServer.java:161) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.glassfish.hk2.utilities.reflection.ReflectionHelper.makeMe(ReflectionHelper.java:1375) at org.jvnet.hk2.internal.Utilities.justCreate(Utilities.java:1083) at org.jvnet.hk2.internal.ServiceLocatorImpl.create(ServiceLocatorImpl.java:978) at org.jvnet.hk2.internal.ServiceLocatorImpl.createAndInitialize(ServiceLocatorImpl.java:1082) at org.jvnet.hk2.internal.ServiceLocatorImpl.createAndInitialize(ServiceLocatorImpl.java:1074) at org.glassfish.jersey.inject.hk2.AbstractHk2InjectionManager.createAndInitialize(AbstractHk2InjectionManager.java:213) at org.glassfish.jersey.inject.hk2.ImmediateHk2InjectionManager.createAndInitialize(ImmediateHk2InjectionManager.java:54) at org.glassfish.jersey.server.ApplicationConfigurator.createApplication(ApplicationConfigurator.java:138) at org.glassfish.jersey.server.ApplicationConfigurator.init(ApplicationConfigurator.java:96) at org.glassfish.jersey.server.ApplicationHandler.lambda$initialize$0(ApplicationHandler.java:313) at java.util.Arrays$ArrayList.forEach(Arrays.java:3880) at org.glassfish.jersey.server.ApplicationHandler.initialize(ApplicationHandler.java:313) at org.glassfish.jersey.server.ApplicationHandler.<init>(ApplicationHandler.java:282) at org.glassfish.jersey.servlet.WebComponent.<init>(WebComponent.java:335) at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:178) at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:370) at javax.servlet.GenericServlet.init(GenericServlet.java:244) at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:670) at org.eclipse.jetty.servlet.ServletHolder.initialize(ServletHolder.java:427) at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:760) at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:374) at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1497) at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1459) at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:848) at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:287) at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:545) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:138) at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:117) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:113) at org.eclipse.jetty.server.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:167) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:138) at org.eclipse.jetty.server.Server.start(Server.java:419) at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:108) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:113) at org.eclipse.jetty.server.Server.doStart(Server.java:386) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.apache.zeppelin.server.ZeppelinServer.main(ZeppelinServer.java:215) WARN [2020-06-04 18:02:26,999] ({main} WebAppContext.java[doStart]:554) - Failed startup of context o.e.j.w.WebAppContext@60611244{zeppelin-web,/,file:///usr/hdp/3.0.1.0-187/zeppelin/webapps/webapp/,UNAVAILABLE}{/usr/hdp/current/zeppelin-server/lib/zeppelin-web-0.8.0.3.0.1.0-187.war} javax.servlet.ServletException: rest@355bd4==org.eclipse.jetty.servlet.NoJspServlet,jsp=rest,order=-1,inst=false at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:691) at org.eclipse.jetty.servlet.ServletHolder.initialize(ServletHolder.java:427) at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:760) at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:374) at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1497) at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1459) at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:848) at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:287) at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:545) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:138) at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:117) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:113) at org.eclipse.jetty.server.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:167) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:138) at org.eclipse.jetty.server.Server.start(Server.java:419) at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:108) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:113) at org.eclipse.jetty.server.Server.doStart(Server.java:386) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.apache.zeppelin.server.ZeppelinServer.main(ZeppelinServer.java:215) Caused by: A MultiException has 1 exceptions. They are: 1. com.google.gson.JsonSyntaxException: duplicate key: colWidth at org.jvnet.hk2.internal.Utilities.justCreate(Utilities.java:1085) at org.jvnet.hk2.internal.ServiceLocatorImpl.create(ServiceLocatorImpl.java:978) at org.jvnet.hk2.internal.ServiceLocatorImpl.createAndInitialize(ServiceLocatorImpl.java:1082) at org.jvnet.hk2.internal.ServiceLocatorImpl.createAndInitialize(ServiceLocatorImpl.java:1074) at org.glassfish.jersey.inject.hk2.AbstractHk2InjectionManager.createAndInitialize(AbstractHk2InjectionManager.java:213) at org.glassfish.jersey.inject.hk2.ImmediateHk2InjectionManager.createAndInitialize(ImmediateHk2InjectionManager.java:54) at org.glassfish.jersey.server.ApplicationConfigurator.createApplication(ApplicationConfigurator.java:138) at org.glassfish.jersey.server.ApplicationConfigurator.init(ApplicationConfigurator.java:96) at org.glassfish.jersey.server.ApplicationHandler.lambda$initialize$0(ApplicationHandler.java:313) at java.util.Arrays$ArrayList.forEach(Arrays.java:3880) at org.glassfish.jersey.server.ApplicationHandler.initialize(ApplicationHandler.java:313) at org.glassfish.jersey.server.ApplicationHandler.<init>(ApplicationHandler.java:282) at org.glassfish.jersey.servlet.WebComponent.<init>(WebComponent.java:335) at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:178) at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:370) at javax.servlet.GenericServlet.init(GenericServlet.java:244) at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:670) ... 21 more Caused by: com.google.gson.JsonSyntaxException: duplicate key: colWidth at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.read(MapTypeAdapterFactory.java:191) at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.read(MapTypeAdapterFactory.java:146) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172) at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40) at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:81) at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172) at com.google.gson.Gson.fromJson(Gson.java:791) at com.google.gson.Gson.fromJson(Gson.java:757) at com.google.gson.Gson.fromJson(Gson.java:706) at com.google.gson.Gson.fromJson(Gson.java:678) at org.apache.zeppelin.notebook.Note.fromJson(Note.java:988) at org.apache.zeppelin.notebook.repo.FileSystemNotebookRepo.get(FileSystemNotebookRepo.java:68) at org.apache.zeppelin.notebook.repo.NotebookRepoSync.get(NotebookRepoSync.java:165) at org.apache.zeppelin.notebook.Notebook.loadNoteFromRepo(Notebook.java:505) at org.apache.zeppelin.notebook.Notebook.loadAllNotes(Notebook.java:589) at org.apache.zeppelin.notebook.Notebook.<init>(Notebook.java:123) at org.apache.zeppelin.server.ZeppelinServer.<init>(ZeppelinServer.java:161) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.glassfish.hk2.utilities.reflection.ReflectionHelper.makeMe(ReflectionHelper.java:1375) at org.jvnet.hk2.internal.Utilities.justCreate(Utilities.java:1083) ... 37 more INFO [2020-06-04 18:02:27,022] ({main} AbstractConnector.java[doStart]:289) - Started ServerConnector@5d0e703a{HTTP/1.1,[http/1.1]}{0.0.0.0:9995} INFO [2020-06-04 18:02:27,023] ({main} Server.java[doStart]:411) - Started @21690ms INFO [2020-06-04 18:02:27,023] ({main} ZeppelinServer.java[main]:223) - Done, zeppelin server started           ... 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