java.lang.NullPointerException
        at org.netbeans.modules.java.source.indexing.MultiPassCompileWorker.compile(MultiPassCompileWorker.java:294)
        at org.netbeans.modules.java.source.indexing.JavaCustomIndexer$1$1.run(JavaCustomIndexer.java:131)
        at org.netbeans.modules.java.source.indexing.JavaCustomIndexer$1$1.run(JavaCustomIndexer.java:116)
Caused: java.io.IOException
        at org.netbeans.modules.java.source.tasklist.TaskCache.refreshTransaction(TaskCache.java:472)
        at org.netbeans.modules.java.source.indexing.JavaCustomIndexer$1.run(JavaCustomIndexer.java:116)
        at org.netbeans.modules.java.source.indexing.JavaCustomIndexer$1.run(JavaCustomIndexer.java:114)
        at org.netbeans.modules.java.source.usages.ClassIndexManager.writeLock(ClassIndexManager.java:100)
        at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:114)
        at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:141)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:818)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.scanSource(RepositoryUpdater.java:1394)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.scanSources(RepositoryUpdater.java:1368)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.getDone(RepositoryUpdater.java:1184)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$2.getDone(RepositoryUpdater.java:616)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:874)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:1637)
        at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:1609)
        at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:601)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
        at java.util.concurrent.FutureTask.run(FutureTask.java:166)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
        at java.lang.Thread.run(Thread.java:717)