java.lang.NullPointerException
        at org.netbeans.modules.java.source.util.LowMemoryNotifier.addLowMemoryListener(LowMemoryNotifier.java:103)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater.batchCompile(RepositoryUpdater.java:3063)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater.access$4900(RepositoryUpdater.java:160)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.parseFiles(RepositoryUpdater.java:2216)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.updateFolder(RepositoryUpdater.java:2316)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.scanRoots(RepositoryUpdater.java:1849)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.access$2700(RepositoryUpdater.java:1292)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker$1.run(RepositoryUpdater.java:1443)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker$1.run(RepositoryUpdater.java:1335)
        at org.netbeans.modules.java.source.usages.ClassIndexManager.writeLock(ClassIndexManager.java:99)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.run(RepositoryUpdater.java:1332)
        at org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.run(RepositoryUpdater.java:1292)
        at org.netbeans.api.java.source.JavaSource$CompilationJob.run(JavaSource.java:1618)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)