java.lang.NoClassDefFoundError: org/netbeans/modules/scala/maven/MavenProjectOpenedHook
   at org.netbeans.modules.scala.maven.MavenProjectOpenedHookLookupProvider.createAdditionalLookup(MavenProjectOpenedHookLookupProvider.java:29)
   at org.netbeans.spi.project.support.DelegatingLookupImpl.doDelegate(DelegatingLookupImpl.java:139)
   at org.netbeans.spi.project.support.DelegatingLookupImpl.resultChanged(DelegatingLookupImpl.java:103)
   at org.openide.util.lookup.ProxyLookup$1Notify.run(ProxyLookup.java:180)
   at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:189)
   at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:125)
   at org.netbeans.modules.projectapi.LazyLookupProviders$1Prov$1.beforeLookup(LazyLookupProviders.java:120)
   at org.openide.util.lookup.ProxyLookup.beforeLookup(ProxyLookup.java:209)
   at org.openide.util.lookup.ProxyLookup$R.myBeforeLookup(ProxyLookup.java:671)
   at org.openide.util.lookup.ProxyLookup$R.beforeLookup(ProxyLookup.java:693)
   at org.openide.util.lookup.ProxyLookup$LazyCollection.computeDelegate(ProxyLookup.java:1121)
   at org.openide.util.lookup.ProxyLookup$LazyCollection.access$900(ProxyLookup.java:1051)
   at org.openide.util.lookup.ProxyLookup$LazyCollection$1.hasNext(ProxyLookup.java:1251)
   at org.netbeans.spi.project.support.LookupProviderSupport$MergedSharabilityQueryImplementation2.getSharability(LookupProviderSupport.java:323)
   at org.netbeans.modules.projectapi.ProjectSharabilityQuery2.getSharability(ProjectSharabilityQuery2.java:67)
   at org.netbeans.api.queries.SharabilityQuery.getSharability(SharabilityQuery.java:177)
   at org.netbeans.modules.subversion.Subversion.isIgnored(Subversion.java:426)
   at org.netbeans.modules.subversion.FileStatusCache.createMissingEntryFileInformation(FileStatusCache.java:1134)
   at org.netbeans.modules.subversion.FileStatusCache.createFileInformation(FileStatusCache.java:952)
   at org.netbeans.modules.subversion.FileStatusCache.scanFolder(FileStatusCache.java:920)
   at org.netbeans.modules.subversion.FileStatusCache.getScannedFiles(FileStatusCache.java:854)
   at org.netbeans.modules.subversion.FileStatusCache.getStatus(FileStatusCache.java:418)
   at org.netbeans.modules.subversion.FileStatusCache.createMissingEntryFileInformation(FileStatusCache.java:1088)
   at org.netbeans.modules.subversion.FileStatusCache.createFileInformation(FileStatusCache.java:952)
   at org.netbeans.modules.subversion.FileStatusCache.scanFolder(FileStatusCache.java:929)
   at org.netbeans.modules.subversion.FileStatusCache.getScannedFiles(FileStatusCache.java:854)
   at org.netbeans.modules.subversion.FileStatusCache.refresh(FileStatusCache.java:548)
   at org.netbeans.modules.subversion.FileStatusCache.refresh(FileStatusCache.java:501)
   at org.netbeans.modules.subversion.FilesystemHandler$3.run(FilesystemHandler.java:555)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)
   at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:68)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:303)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2058)