java.util.ConcurrentModificationException
   at java.util.IdentityHashMap$Values.toArray(IdentityHashMap.java:1119)
   at java.util.IdentityHashMap$Values.toArray(IdentityHashMap.java:1098)
   at java.util.ArrayList.<init>(ArrayList.java:151)
   at com.google.common.collect.Lists.newArrayList(Lists.java:119)
   at com.google.inject.internal.Initializer.injectAll(Initializer.java:94)
   at com.google.inject.internal.InternalInjectorCreator.injectDynamically(InternalInjectorCreator.java:174)
   at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:110)
   at com.google.inject.Guice.createInjector(Guice.java:94)
   at com.google.inject.Guice.createInjector(Guice.java:71)
   at com.google.inject.Guice.createInjector(Guice.java:61)
   at org.codehaus.plexus.DefaultPlexusContainer.addPlexusInjector(DefaultPlexusContainer.java:470)
   at org.codehaus.plexus.DefaultPlexusContainer.<init>(DefaultPlexusContainer.java:196)
   at org.codehaus.plexus.DefaultPlexusContainer.<init>(DefaultPlexusContainer.java:160)
   at org.netbeans.modules.maven.embedder.EmbedderFactory.createOnlineEmbedder(EmbedderFactory.java:364)
   at org.netbeans.modules.maven.embedder.EmbedderFactory.getOnlineEmbedder(EmbedderFactory.java:348)
   at org.netbeans.modules.maven.embedder.impl.MavenProtocolHandler.openConnection(MavenProtocolHandler.java:81)
   at java.net.URL.openConnection(URL.java:972)
   at org.netbeans.modules.autoupdate.services.InstallSupportImpl.externalDownload(InstallSupportImpl.java:1297)
   at org.netbeans.modules.autoupdate.services.InstallSupportImpl.doDownload(InstallSupportImpl.java:759)
   at org.netbeans.modules.autoupdate.services.InstallSupportImpl.doDownload(InstallSupportImpl.java:679)
   at org.netbeans.modules.autoupdate.services.InstallSupportImpl.access$700(InstallSupportImpl.java:91)
   at org.netbeans.modules.autoupdate.services.InstallSupportImpl$1.call(InstallSupportImpl.java:193)
   at org.netbeans.modules.autoupdate.services.InstallSupportImpl$1.call(InstallSupportImpl.java:134)
   at java.util.concurrent.FutureTask.run(FutureTask.java:262)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
   at java.lang.Thread.run(Thread.java:722)
Caused: java.util.concurrent.ExecutionException: java.util.ConcurrentModificationException
   at java.util.concurrent.FutureTask.report(FutureTask.java:122)
   at java.util.concurrent.FutureTask.get(FutureTask.java:188)
   at org.netbeans.modules.autoupdate.services.InstallSupportImpl.doDownload(InstallSupportImpl.java:216)
   at org.netbeans.api.autoupdate.InstallSupport.doDownload(InstallSupport.java:116)
   at org.netbeans.modules.autoupdate.ui.wizards.InstallStep.tryPerformDownload(InstallStep.java:356)
   at org.netbeans.modules.autoupdate.ui.wizards.InstallStep.handleDownload(InstallStep.java:252)
   at org.netbeans.modules.autoupdate.ui.wizards.InstallStep.doDownloadAndVerificationAndInstall(InstallStep.java:211)
   at org.netbeans.modules.autoupdate.ui.wizards.InstallStep.access$200(InstallStep.java:106)
   at org.netbeans.modules.autoupdate.ui.wizards.InstallStep$2.run(InstallStep.java:203)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1454)
   at org.openide.util.RequestProcessor$Processor.doEvaluate(RequestProcessor.java:2100)
   at org.openide.util.RequestProcessor$Task.waitFinished(RequestProcessor.java:1688)
   at org.netbeans.modules.autoupdate.ui.wizards.InstallStep$1.propertyChange(InstallStep.java:186)
   at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
   at java.awt.Component.firePropertyChange(Component.java:8414)
   at org.netbeans.modules.autoupdate.ui.wizards.OperationPanel.access$200(OperationPanel.java:67)
   at org.netbeans.modules.autoupdate.ui.wizards.OperationPanel$1.run(OperationPanel.java:105)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1454)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2048)