How to reproduce :

• use demo repository
• open the CMS of the blog
  > the home page is automaticaly opened with this error 500

  HTTP ERROR 500
  
  Problem accessing /cms/blog/fr/index.html. Reason:
  
      INTERNAL_SERVER_ERROR
  
  Caused by:
  
  java.lang.AbstractMethodError
  	at org.ametys.web.inputdata.SitemapInputData._saxPages(SitemapInputData.java:172)
  	at org.ametys.web.inputdata.SitemapInputData.toSAX(SitemapInputData.java:137)
  	at org.ametys.web.inputdata.InputDataGenerator.generate(InputDataGenerator.java:144)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.processXMLPipeline(AbstractProcessingPipeline.java:579)
  	at org.apache.cocoon.components.pipeline.impl.AbstractCachingProcessingPipeline.processXMLPipeline(AbstractCachingProcessingPipeline.java:280)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.process(AbstractProcessingPipeline.java:780)
  	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:579)
  	at org.apache.cocoon.components.pipeline.impl.AbstractCachingProcessingPipeline.processXMLPipeline(AbstractCachingProcessingPipeline.java:280)
  	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.process(AbstractProcessingPipeline.java:481)
  	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.apache.cocoon.servlet.CocoonServlet.service(CocoonServlet.java:1159)
  	at org.ametys.runtime.servlet.RuntimeServlet._doService(RuntimeServlet.java:135)
  	at org.ametys.runtime.servlet.RuntimeServlet.service(RuntimeServlet.java:92)
  	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
  	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
  	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:390)
  	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
  	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
  	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
  	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
  	at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
  	at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
  	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
  	at org.mortbay.jetty.Server.handle(Server.java:326)
  	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:536)
  	at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:915)
  	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:539)
  	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
  	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:405)
  	at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
  	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)