java.lang.NullPointerException
   at org.apache.maven.repository.legacy.resolver.DefaultLegacyArtifactCollector.getManagedVersionsMap(DefaultLegacyArtifactCollector.java:222)
   at org.apache.maven.repository.legacy.resolver.DefaultLegacyArtifactCollector.collect(DefaultLegacyArtifactCollector.java:140)
   at org.apache.maven.repository.legacy.resolver.DefaultLegacyArtifactCollector.collect(DefaultLegacyArtifactCollector.java:100)
   at org.apache.maven.repository.legacy.resolver.DefaultLegacyArtifactCollector.collect(DefaultLegacyArtifactCollector.java:782)
   at org.apache.maven.shared.dependency.tree.DefaultDependencyTreeBuilder.buildDependencyTree(DefaultDependencyTreeBuilder.java:97)
   at org.netbeans.modules.maven.embedder.DependencyTreeFactory.createDependencyTree(DependencyTreeFactory.java:93)
   at org.netbeans.modules.maven.embedder.DependencyTreeFactory.createDependencyTree(DependencyTreeFactory.java:78)
   at org.netbeans.modules.maven.repository.ui.ArtifactMultiViewFactory$1.run(ArtifactMultiViewFactory.java:189)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1973)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.NullPointerException
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:425)
   at org.netbeans.modules.maven.repository.ui.ArtifactMultiViewFactory.createTopComponent(ArtifactMultiViewFactory.java:137)
   at org.netbeans.modules.maven.repository.ui.ArtifactMultiViewFactory.createTopComponent(ArtifactMultiViewFactory.java:117)
   at org.netbeans.modules.maven.indexer.api.ui.ArtifactViewer.showArtifactViewer(ArtifactViewer.java:124)
   at org.netbeans.modules.maven.indexer.api.ui.ArtifactViewer.showArtifactViewer(ArtifactViewer.java:113)
   at org.netbeans.modules.maven.graph.ShowGraphAction.actionPerformed(ShowGraphAction.java:90)
   at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
   at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
   at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
   at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
   at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
   at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
   at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
   at java.awt.Component.processMouseEvent(Component.java:6504)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
   at java.awt.Component.processEvent(Component.java:6269)
   at java.awt.Container.processEvent(Container.java:2229)
   at java.awt.Component.dispatchEventImpl(Component.java:4860)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4686)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4832)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4492)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4422)
   at java.awt.Container.dispatchEventImpl(Container.java:2273)
   at java.awt.Window.dispatchEventImpl(Window.java:2713)
   at java.awt.Component.dispatchEvent(Component.java:4686)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
   at java.awt.EventQueue.access$000(EventQueue.java:101)
   at java.awt.EventQueue$3.run(EventQueue.java:666)
   at java.awt.EventQueue$3.run(EventQueue.java:664)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
   at java.awt.EventQueue$4.run(EventQueue.java:680)
   at java.awt.EventQueue$4.run(EventQueue.java:678)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:153)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)