java.lang.IllegalStateException: Node has been removed. at java.util.prefs.AbstractPreferences.get(AbstractPreferences.java:283) at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider$AuxiliaryConfigBasedPreferences.access$1601(AuxiliaryConfigBasedPreferencesProvider.java:428) at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider$AuxiliaryConfigBasedPreferences$2.run(AuxiliaryConfigBasedPreferencesProvider.java:657) at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider$AuxiliaryConfigBasedPreferences$2.run(AuxiliaryConfigBasedPreferencesProvider.java:655) at org.openide.util.Mutex.readAccess(Mutex.java:295) at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider$AuxiliaryConfigBasedPreferences.get(AuxiliaryConfigBasedPreferencesProvider.java:655) at org.netbeans.modules.editor.indent.project.ProxyPreferences$PrefTracker.preferenceChange(ProxyPreferences.java:233) at sun.reflect.GeneratedMethodAccessor27.invoke(GeneratedMethodAccessor27.java:0) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:483) at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:461) at com.sun.proxy.$Proxy12.preferenceChange(.java:0) at java.util.prefs.AbstractPreferences$EventDispatchThread.run(AbstractPreferences.java:1496)