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$2.run(ArtifactMultiViewFactory.java:228)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1452)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2032)