java.lang.NullPointerException
   at com.sun.tools.javac.code.Types$DescriptorFilter.accepts(Types.java:723)
   at com.sun.tools.javac.code.Types$DescriptorFilter.accepts(Types.java:713)
   at com.sun.tools.javac.code.Scope$2$1.skipToNextMatchingEntry(Scope.java:410)
   at com.sun.tools.javac.code.Scope$2$1.update(Scope.java:401)
   at com.sun.tools.javac.code.Scope$2$1.<init>(Scope.java:380)
   at com.sun.tools.javac.code.Scope$2.iterator(Scope.java:376)
   at com.sun.tools.javac.code.Scope$CompoundScope$1$1.nextIterator(Scope.java:661)
   at com.sun.tools.javac.code.Scope$CompoundScope$CompoundScopeIterator.update(Scope.java:711)
   at com.sun.tools.javac.code.Scope$CompoundScope$CompoundScopeIterator.<init>(Scope.java:688)
   at com.sun.tools.javac.code.Scope$CompoundScope$1$1.<init>(Scope.java:659)
   at com.sun.tools.javac.code.Scope$CompoundScope$1.iterator(Scope.java:659)
   at com.sun.tools.javac.code.Types$DescriptorCache.findDescriptorInternal(Types.java:412)
   at com.sun.tools.javac.code.Types$DescriptorCache.get(Types.java:391)
   at com.sun.tools.javac.code.Types.findDescriptorSymbol(Types.java:560)
   at com.sun.tools.javac.code.Types.isFunctionalInterface(Types.java:576)
   at com.sun.tools.javac.comp.Resolve$MostSpecificCheck$MostSpecificCheckContext.unrelatedFunctionalInterfaces(Resolve.java:1114)
   at com.sun.tools.javac.comp.Resolve$MostSpecificCheck$MostSpecificCheckContext.compatible(Resolve.java:1099)
   at com.sun.tools.javac.comp.Check.checkType(Check.java:557)
   at com.sun.tools.javac.comp.Attr$ResultInfo.check(Attr.java:478)
   at com.sun.tools.javac.comp.Resolve$MostSpecificCheck.argumentsAcceptable(Resolve.java:1068)
   at com.sun.tools.javac.comp.Resolve.rawInstantiate(Resolve.java:584)
   at com.sun.tools.javac.comp.Resolve.instantiate(Resolve.java:629)
   at com.sun.tools.javac.comp.Resolve.signatureMoreSpecific(Resolve.java:1565)
   at com.sun.tools.javac.comp.Resolve.mostSpecific(Resolve.java:1495)
   at com.sun.tools.javac.comp.Resolve.selectBest(Resolve.java:1468)
   at com.sun.tools.javac.comp.Resolve.findMethodInScope(Resolve.java:1633)
   at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1704)
   at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1677)
   at com.sun.tools.javac.comp.Resolve$9.doLookup(Resolve.java:2437)
   at com.sun.tools.javac.comp.Resolve$BasicLookupHelper.lookup(Resolve.java:3096)
   at com.sun.tools.javac.comp.Resolve.lookupMethod(Resolve.java:3347)
   at com.sun.tools.javac.comp.Resolve.resolveQualifiedMethod(Resolve.java:2434)
   at com.sun.tools.javac.comp.Resolve.resolveQualifiedMethod(Resolve.java:2428)
   at com.sun.tools.javac.comp.Attr.selectSym(Attr.java:3575)
   at com.sun.tools.javac.comp.Attr.visitSelect(Attr.java:3457)
   at com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:1903)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.visitApply(Attr.java:1844)
   at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1471)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:621)
   at com.sun.tools.javac.comp.Attr.visitExec(Attr.java:1609)
   at com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1302)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:641)
   at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:657)
   at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1130)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitBlock(NBAttr.java:82)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:915)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:641)
   at com.sun.tools.javac.comp.Attr.visitWhileLoop(Attr.java:1146)
   at com.sun.tools.javac.tree.JCTree$JCWhileLoop.accept(JCTree.java:971)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:641)
   at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:657)
   at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1130)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitBlock(NBAttr.java:82)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:915)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:641)
   at com.sun.tools.javac.comp.Attr.visitMethodDef(Attr.java:1014)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitMethodDef(NBAttr.java:76)
   at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:784)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:641)
   at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:4560)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4462)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4390)
   at com.sun.tools.javac.comp.Attr.attrib(Attr.java:4365)
   at com.sun.tools.javac.main.JavaCompiler.attribute(JavaCompiler.java:1317)
   at com.sun.tools.javac.api.JavacTaskImpl$1.process(JavacTaskImpl.java:473)
   at com.sun.tools.javac.api.JavacTaskImpl$Filter.run(JavacTaskImpl.java:623)
   at com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:476)
   at org.netbeans.modules.java.source.indexing.MultiPassCompileWorker.compile(MultiPassCompileWorker.java:268)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:251)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:161)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:296)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:159)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:2745)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$400(RepositoryUpdater.java:2149)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2631)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2629)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:564)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:2629)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork$4.call(RepositoryUpdater.java:5693)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork$4.call(RepositoryUpdater.java:5601)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$3.run(RepositoryUpdater.java:2122)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:304)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2118)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2099)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.access$1100(RepositoryUpdater.java:157)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSource(RepositoryUpdater.java:5728)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSources(RepositoryUpdater.java:5398)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.getDone(RepositoryUpdater.java:5016)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3402)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:6166)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.access$4300(RepositoryUpdater.java:5813)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3$1.run(RepositoryUpdater.java:6084)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:304)
   at org.netbeans.modules.parsing.impl.RunWhenScanFinishedSupport.performScan(RunWhenScanFinishedSupport.java:106)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:6080)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:6076)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:6076)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
   at java.util.concurrent.FutureTask.run(FutureTask.java:266)
   at org.openide.util.RequestProcessor$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)