When Netbeans starts up, this exception occurs:

java.lang.NoClassDefFoundError: Could not initialize class com.sun.jna.Native
	at org.netbeans.modules.masterfs.watcher.linux.LinuxNotifier.<init>(LinuxNotifier.java:103)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
	at java.lang.Class.newInstance0(Class.java:355)
	at java.lang.Class.newInstance(Class.java:308)
	at org.openide.util.lookup.implspi.SharedClassObjectBridge.newInstance(SharedClassObjectBridge.java:64)
[catch] at org.openide.util.lookup.MetaInfServicesLookup$P.getInstance(MetaInfServicesLookup.java:519)
	at org.netbeans.modules.masterfs.watcher.Watcher.getNotifierForPlatform(Watcher.java:414)
	at org.netbeans.modules.masterfs.watcher.Watcher.<init>(Watcher.java:85)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
	at java.lang.Class.newInstance0(Class.java:355)
	at java.lang.Class.newInstance(Class.java:308)
	at org.openide.util.lookup.implspi.SharedClassObjectBridge.newInstance(SharedClassObjectBridge.java:64)
	at org.openide.util.lookup.MetaInfServicesLookup$P.getInstance(MetaInfServicesLookup.java:519)
	at org.openide.util.lookup.AbstractLookup$R.allInstances(AbstractLookup.java:1041)
	at org.openide.util.lookup.AbstractLookup$R.allInstances(AbstractLookup.java:1021)
	at org.openide.util.lookup.ProxyLookup$LazyCollection.computeSingleResult(ProxyLookup.java:1249)
	at org.openide.util.lookup.ProxyLookup$LazyCollection.computeDelegate(ProxyLookup.java:1091)
	at org.openide.util.lookup.ProxyLookup$LazyCollection.access$900(ProxyLookup.java:1021)
	at org.openide.util.lookup.ProxyLookup$LazyCollection$1.hasNext(ProxyLookup.java:1215)
	at org.netbeans.modules.masterfs.filebasedfs.FileBasedFileSystem$StatusImpl.resultChanged(FileBasedFileSystem.java:305)
	at org.netbeans.modules.masterfs.filebasedfs.FileBasedFileSystem$StatusImpl.<init>(FileBasedFileSystem.java:271)
	at org.netbeans.modules.masterfs.filebasedfs.FileBasedFileSystem.<init>(FileBasedFileSystem.java:81)
	at org.netbeans.modules.masterfs.filebasedfs.FileBasedFileSystem.<clinit>(FileBasedFileSystem.java:79)
	at org.netbeans.modules.masterfs.filebasedfs.FileBasedURLMapper.getFileObjects(FileBasedURLMapper.java:138)
	at org.netbeans.modules.masterfs.MasterURLMapper.getFileObjects(MasterURLMapper.java:65)
	at org.openide.filesystems.URLMapper.findFileObject(URLMapper.java:212)
	at org.netbeans.modules.project.ui.LazyProject.getProjectDirectory(LazyProject.java:92)
	at org.netbeans.modules.project.ui.OpenProjectList$RecentProjectList$4.run(OpenProjectList.java:1537)
	at org.netbeans.modules.project.ui.OpenProjectList$RecentProjectList$4.run(OpenProjectList.java:1505)
	at org.openide.util.Mutex.readAccess(Mutex.java:290)
	at org.netbeans.modules.project.ui.OpenProjectList$RecentProjectList.load(OpenProjectList.java:1505)
	at org.netbeans.modules.project.ui.OpenProjectList$2.run(OpenProjectList.java:215)
	at org.netbeans.modules.project.ui.OpenProjectList$2.run(OpenProjectList.java:208)
	at org.openide.util.Mutex.readAccess(Mutex.java:290)
	at org.netbeans.modules.project.ui.OpenProjectList.getDefault(OpenProjectList.java:208)
	at org.netbeans.modules.project.ui.OpenProjectsTrampolineImpl.addPropertyChangeListenerAPI(OpenProjectsTrampolineImpl.java:95)
	at org.netbeans.api.project.ui.OpenProjects.addPropertyChangeListener(OpenProjects.java:287)
	at org.netbeans.api.project.ui.OpenProjects.<init>(OpenProjects.java:98)
	at org.netbeans.api.project.ui.OpenProjects.<clinit>(OpenProjects.java:90)
	at org.netbeans.modules.editor.bookmarks.BookmarksPersistence.initProjectsListening(BookmarksPersistence.java:105)
	at org.netbeans.modules.editor.bookmarks.EditorBookmarksModule.restored(EditorBookmarksModule.java:77)
	at org.netbeans.core.startup.NbInstaller.loadCode(NbInstaller.java:450)
	at org.netbeans.core.startup.NbInstaller.load(NbInstaller.java:383)
	at org.netbeans.ModuleManager.enable(ModuleManager.java:1163)
	at org.netbeans.ModuleManager.enable(ModuleManager.java:986)
	at org.netbeans.core.startup.ModuleList.installNew(ModuleList.java:340)
	at org.netbeans.core.startup.ModuleList.trigger(ModuleList.java:276)
	at org.netbeans.core.startup.ModuleSystem.restore(ModuleSystem.java:295)
	at org.netbeans.core.startup.Main.getModuleSystem(Main.java:169)
	at org.netbeans.core.startup.Main.start(Main.java:305)
	at org.netbeans.core.startup.TopThreadGroup.run(TopThreadGroup.java:123)
	at java.lang.Thread.run(Thread.java:662)