Caused: java.lang.NullPointerException
        at org.openide.filesystems.XMLMapAttr.getAttribute(XMLMapAttr.java:195)
        at org.openide.filesystems.XMLMapAttr.getAttribute(XMLMapAttr.java:178)
[catch] at org.openide.filesystems.DefaultAttributes$Table.getAttr(DefaultAttributes.java:825)
        at org.openide.filesystems.DefaultAttributes.readAttribute(DefaultAttributes.java:381)
        at org.openide.filesystems.LocalFileSystem$InnerAttrs.readAttribute(LocalFileSystem.java:700)
        at org.netbeans.core.startup.layers.LocalFileSystemEx$DelegatingAttributes.readAttribute(LocalFileSystemEx.java:203)
        at org.openide.filesystems.AbstractFileObject.getAttribute(AbstractFileObject.java:323)
        at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:824)
        at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:786)
        at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:822)
        at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:786)
        at org.openide.filesystems.MultiFileObject.getAttribute(MultiFileObject.java:719)
        at org.openide.loaders.InstanceDataObject$Ser.getClassName(InstanceDataObject.java:1160)
        at org.openide.loaders.InstanceDataObject$Ser.instanceName(InstanceDataObject.java:1143)
        at org.openide.loaders.InstanceSupport.instanceClass(InstanceSupport.java:145)
        at org.openide.loaders.InstanceDataObject$Ser.instanceClass(InstanceDataObject.java:1204)
        at org.openide.loaders.InstanceDataObject.instanceClass(InstanceDataObject.java:727)
        at org.netbeans.modules.editor.impl.SideBarFactoriesProvider.computeInstances(SideBarFactoriesProvider.java:124)
        at org.netbeans.modules.editor.impl.SideBarFactoriesProvider.getFactories(SideBarFactoriesProvider.java:84)
        at org.netbeans.modules.editor.impl.CustomizableSideBar.getFactoriesMap(CustomizableSideBar.java:259)
        at org.netbeans.modules.editor.NbEditorKit.call(NbEditorKit.java:867)
        at org.openide.text.CloneableEditor$DoInitialize.initNonVisual(CloneableEditor.java:339)
        at org.openide.text.CloneableEditor$DoInitialize.run(CloneableEditor.java:249)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)
ALL [null]: fileName = org-netbeans-modules-editor-gsfret-GsfCodeFoldingSideBarFactory.instance