java.lang.NullPointerException 
    at org.ametys.plugins.contentio.synchronize.SynchronizableContentsCollectionMetadataProvider.lambda$getExternalAndLocalMetadata$5(SynchronizableContentsCollectionMetadataProvider.java:74) 
    at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) 
    at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) 
    at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374) 
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) 
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) 
    at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) 
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) 
    at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) 
    at org.ametys.plugins.contentio.synchronize.SynchronizableContentsCollectionMetadataProvider.getExternalAndLocalMetadata(SynchronizableContentsCollectionMetadataProvider.java:76) 
    at org.ametys.cms.content.external.ExternalizableMetadataProviderExtensionPoint.getExternalAndLocalMetadata(ExternalizableMetadataProviderExtensionPoint.java:45) 
    at org.ametys.cms.contenttype.MetadataManager.getExternalizableMetadata(MetadataManager.java:99) 
    at org.ametys.cms.contenttype.MetadataManager.saxMetadata(MetadataManager.java:163) 
    at org.ametys.cms.content.ContentGenerator._saxMetadata(ContentGenerator.java:374) 
    at org.ametys.cms.content.ContentGenerator._saxContent(ContentGenerator.java:172) 
    at org.ametys.cms.content.ContentGenerator._generateContent(ContentGenerator.java:121) 
    at org.ametys.cms.content.ContentGenerator.generate(ContentGenerator.java:105) 
    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.source.impl.SitemapSource.getInputStream(SitemapSource.java:267) 
    at org.ametys.core.ui.dispatcher.DispatchGenerator._dispatching(DispatchGenerator.java:151) 
    at org.ametys.core.ui.dispatcher.DispatchGenerator.generate(DispatchGenerator.java:91) 
    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.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.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:543) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) 
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) 
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) 
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799) 
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) 
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) 
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455) 
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 
    at java.util.concurrent.ThreadPoolExecutor$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)