How to reproduce

• connect to back-office
• create a page
• insert service user preference

Actual behavior

• An error is displayed (see screenshot)
• this is the trace of the error:

  java.lang.NullPointerException at org.ametys.plugins.core.userpref.UserPreferencesGenerator.generate(UserPreferencesGenerator.java:86) 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: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.toSAX(SourceUtil.java:181) at org.apache.cocoon.components.source.SourceUtil.toSAX(SourceUtil.java:140) at org.ametys.web.repository.PageGenerator._saxSource(PageGenerator.java:616) at org.ametys.web.repository.PageGenerator._saxZoneItem(PageGenerator.java:576) 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:537) 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:217) 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:616) 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$AbstractConnectionHandler.process(AbstractProtocol.java:673) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source)