How to reproduce :

• use the demo skin,
• In a page inserts the attachment service with the tree view display
  > an error occurs :

  Date:			Tue Jun 28 10:09:22 CEST 2016 (1467101362368)
  Thread:		http-apr-8122-exec-6
  Message #:	6302
  Level:		ERROR
  NDC:			
  Category:	org.ametys.web.repository.PageGenerator
  Message:		Unable to display zone item
  Location:	org.apache.cocoon.util.log.SLF4JLoggerAdapter.error(SLF4JLoggerAdapter.java:46)
  Thrown:
  org.apache.cocoon.ProcessingException: Unable to get transformer handler for file:/D:/Dev/Projets/AggloCarcassonne/siteweb/AggloCarcassonne-cms/web/skins/carcassonne/services/web/pages/services/attach/attachments-tree_3.3.xsl
  	at [TransformerException] - file:/D:/Dev/Projets/AggloCarcassonne/siteweb/AggloCarcassonne-cms/web/skins/carcassonne/services/web/pages/services/attach/attachments_small_3.3.xsl:24:88
  	at <map:serialize type="xhtml"> - resource://org/ametys/web/sitemap-front.xmap:251:34
  	at <map:transform type="i18n"> - resource://org/ametys/web/sitemap-front.xmap:247:32
  	at <map:transform> - resource://org/ametys/web/sitemap-front.xmap:246:43
  	at <map:transform type="i18n"> - resource://org/ametys/web/sitemap-front.xmap:243:32
  	at <map:generate type="attachments"> - resource://org/ametys/web/sitemap-front.xmap:240:38
  	at org.apache.cocoon.transformation.TraxTransformer.setup(TraxTransformer.java:339)
  	at org.ametys.runtime.cocoon.TraxTransformer.setup(TraxTransformer.java:50)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.setupPipeline(AbstractProcessingPipeline.java:400)
  	at org.apache.cocoon.components.pipeline.impl.AbstractCachingProcessingPipeline.setupPipeline(AbstractCachingProcessingPipeline.java:738)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.preparePipeline(AbstractProcessingPipeline.java:503)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.prepareInternal(AbstractProcessingPipeline.java:517)
  	at org.apache.cocoon.components.source.impl.SitemapSource.init(SitemapSource.java:343)
  	at org.apache.cocoon.components.source.impl.SitemapSource.<init>(SitemapSource.java:215)
  	at org.apache.cocoon.components.source.impl.SitemapSourceFactory.getSource(SitemapSourceFactory.java:68)
  	at org.apache.excalibur.source.impl.SourceResolverImpl.resolveURI(SourceResolverImpl.java:208)
  	at org.apache.cocoon.components.CocoonComponentManager.resolveURI(CocoonComponentManager.java:558)
  	at org.apache.cocoon.components.CocoonComponentManager.resolveURI(CocoonComponentManager.java:558)
  	at org.apache.cocoon.environment.AbstractEnvironment.resolveURI(AbstractEnvironment.java:555)
  	at org.apache.cocoon.environment.wrapper.MutableEnvironmentFacade.resolveURI(MutableEnvironmentFacade.java:307)
  	at org.ametys.web.repository.PageGenerator._saxZoneItem(PageGenerator.java:570)
  	at org.ametys.web.repository.PageGenerator._saxZoneItems(PageGenerator.java:391)
  	at org.ametys.web.repository.PageGenerator._saxZone(PageGenerator.java:318)
  	at org.ametys.web.repository.PageGenerator.generate(PageGenerator.java:238)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.processXMLPipeline(AbstractProcessingPipeline.java:581)
  	at org.apache.cocoon.components.pipeline.impl.AbstractCachingProcessingPipeline.processXMLPipeline(AbstractCachingProcessingPipeline.java:301)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.process(AbstractProcessingPipeline.java:782)
  	at org.apache.cocoon.components.source.impl.SitemapSource.toSAX(SitemapSource.java:414)
  	at org.apache.cocoon.components.source.SourceUtil.toSAX(SourceUtil.java:101)
  	at org.apache.cocoon.components.source.SourceUtil.parse(SourceUtil.java:321)
  	at org.apache.cocoon.sitemap.ContentAggregator.generate(ContentAggregator.java:125)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.processXMLPipeline(AbstractProcessingPipeline.java:581)
  	at org.apache.cocoon.components.pipeline.impl.AbstractCachingProcessingPipeline.processXMLPipeline(AbstractCachingProcessingPipeline.java:301)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.process(AbstractProcessingPipeline.java:483)
  	at org.apache.cocoon.components.treeprocessor.sitemap.SerializeNode.invoke(SerializeNode.java:144)
  	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:47)
  	at org.apache.cocoon.components.treeprocessor.sitemap.MatchNode.invoke(MatchNode.java:108)
  	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:69)
  	at org.apache.cocoon.components.treeprocessor.sitemap.PipelineNode.invoke(PipelineNode.java:143)
  	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:69)
  	at org.apache.cocoon.components.treeprocessor.sitemap.PipelinesNode.invoke(PipelinesNode.java:93)
  	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:236)
  	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:178)
  	at org.apache.cocoon.components.treeprocessor.TreeProcessor.process(TreeProcessor.java:254)
  	at org.apache.cocoon.components.treeprocessor.sitemap.MountNode.invoke(MountNode.java:118)
  	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:47)
  	at org.apache.cocoon.components.treeprocessor.sitemap.MatchNode.invoke(MatchNode.java:108)
  	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:69)
  	at org.apache.cocoon.components.treeprocessor.sitemap.PipelineNode.invoke(PipelineNode.java:143)
  	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:69)
  	at org.apache.cocoon.components.treeprocessor.sitemap.PipelinesNode.invoke(PipelinesNode.java:93)
  	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:236)
  	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:178)
  	at org.apache.cocoon.components.treeprocessor.TreeProcessor.process(TreeProcessor.java:254)
  	at org.apache.cocoon.Cocoon.process(Cocoon.java:699)
  	at org.ametys.runtime.servlet.RuntimeServlet.service(RuntimeServlet.java:542)
  	at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
  	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
  	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
  	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
  	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
  	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
  	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
  	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
  	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:617)
  	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
  	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
  	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
  	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
  	at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2463)
  	at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2452)
  	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
  	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
  	at java.lang.Thread.run(Thread.java:745)
  Caused by: org.apache.excalibur.xml.xslt.XSLTProcessorException: Exception when creating Transformer from file:/D:/Dev/Projets/AggloCarcassonne/siteweb/AggloCarcassonne-cms/web/skins/carcassonne/services/web/pages/services/attach/attachments-tree_3.3.xsl
  	at org.ametys.runtime.cocoon.ThreadSafeTraxProcessor._createTemplates(ThreadSafeTraxProcessor.java:473)
  	at org.ametys.runtime.cocoon.ThreadSafeTraxProcessor._getTemplates(ThreadSafeTraxProcessor.java:258)
  	at org.ametys.runtime.cocoon.ThreadSafeTraxProcessor.getTransformerHandlerAndValidity(ThreadSafeTraxProcessor.java:187)
  	at org.apache.cocoon.transformation.TraxTransformer.setup(TraxTransformer.java:332)
  	... 70 more
  Caused by: javax.xml.transform.TransformerException: Exception d'E-S avec le fichier de la feuille de style : plugin:page-subscription://stylesheets/helpers/page-subscribe.xsl
  	at org.apache.xalan.processor.StylesheetHandler.error(StylesheetHandler.java:904)
  	at org.apache.xalan.processor.StylesheetHandler.error(StylesheetHandler.java:947)
  	at org.apache.xalan.processor.ProcessorInclude.parse(ProcessorInclude.java:322)
  	at org.apache.xalan.processor.ProcessorInclude.startElement(ProcessorInclude.java:158)
  	at org.apache.xalan.processor.StylesheetHandler.startElement(StylesheetHandler.java:623)
  	at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
  	at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
  	at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
  	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
  	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
  	at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
  	at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
  	at org.apache.xalan.processor.ProcessorInclude.parse(ProcessorInclude.java:312)
  	at org.apache.xalan.processor.ProcessorInclude.startElement(ProcessorInclude.java:158)
  	at org.apache.xalan.processor.StylesheetHandler.startElement(StylesheetHandler.java:623)
  	at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
  	at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
  	at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
  	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
  	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
  	at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
  	at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
  	at org.apache.xalan.processor.ProcessorInclude.parse(ProcessorInclude.java:312)
  	at org.apache.xalan.processor.ProcessorInclude.startElement(ProcessorInclude.java:158)
  	at org.apache.xalan.processor.StylesheetHandler.startElement(StylesheetHandler.java:623)
  	at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
  	at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
  	at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
  	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
  	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
  	at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
  	at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
  	at org.apache.excalibur.xml.impl.JaxpParser.parse(JaxpParser.java:315)
  	at org.apache.excalibur.xmlizer.DefaultXMLizer.toSAX(DefaultXMLizer.java:128)
  	at org.ametys.runtime.cocoon.ThreadSafeTraxProcessor._sourceToSAX(ThreadSafeTraxProcessor.java:488)
  	at org.ametys.runtime.cocoon.ThreadSafeTraxProcessor._createTemplates(ThreadSafeTraxProcessor.java:431)
  	... 73 more
  Caused by: java.net.MalformedURLException: unknown protocol: plugin
  	at java.net.URL.<init>(URL.java:593)
  	at java.net.URL.<init>(URL.java:483)
  	at java.net.URL.<init>(URL.java:432)
  	at org.apache.xerces.impl.XMLEntityManager.setupCurrentEntity(Unknown Source)
  	at org.apache.xerces.impl.XMLVersionDetector.determineDocVersion(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  	at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
  	at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
  	at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
  	at org.apache.xalan.processor.ProcessorInclude.parse(ProcessorInclude.java:312)
  	... 115 more