java.lang.NullPointerException
   at org.netbeans.modules.maven.queries.RepositoryForBinaryQueryImpl$SrcResult.preferSources(RepositoryForBinaryQueryImpl.java:510)
   at org.netbeans.api.java.queries.SourceForBinaryQuery$Result2.preferSources(SourceForBinaryQuery.java:228)
   at org.netbeans.modules.maven.problems.MavenModelProblemsProvider.doArtifactChecks(MavenModelProblemsProvider.java:209)
   at org.netbeans.modules.maven.problems.MavenModelProblemsProvider.getProblems(MavenModelProblemsProvider.java:154)
   at org.netbeans.spi.project.ui.support.UILookupMergerSupport$ProjectProblemsProviderImpl.getProblems(UILookupMergerSupport.java:299)
   at org.netbeans.modules.project.ui.problems.BrokenProjectAnnotator$2.run(BrokenProjectAnnotator.java:141)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.NullPointerException
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:419)
   at org.netbeans.modules.project.ui.problems.BrokenProjectAnnotator.annotateIcon(BrokenProjectAnnotator.java:137)
   at org.netbeans.api.project.ProjectUtils$AnnotateIconProxyProjectInformation.updateIcon(ProjectUtils.java:411)
   at org.netbeans.api.project.ProjectUtils$AnnotateIconProxyProjectInformation.getIcon(ProjectUtils.java:431)
   at org.netbeans.modules.project.ui.OpenProjectList.projects2Unloaded(OpenProjectList.java:1417)
   at org.netbeans.modules.project.ui.OpenProjectList.open(OpenProjectList.java:842)
   at org.netbeans.modules.project.ui.OpenProjectList$6.run(OpenProjectList.java:675)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1423)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)