Possible nullpointerexception triggered by MandatoryDocumentInitializerListener

2019-11-27 09:12:30,205 [localhost-startStop-1] ERROR oryDocumentInitializerListener - Failed to get the list of wikis. 
org.xwiki.wiki.manager.WikiManagerException: Failed to get wiki ids
	at org.xwiki.wiki.internal.descriptor.DefaultWikiDescriptorManager.getAllIds(DefaultWikiDescriptorManager.java:106)
	at org.xwiki.extension.xar.internal.doc.MandatoryDocumentInitializerListener.getMandatoryDocuments(MandatoryDocumentInitializerListener.java:143)
	at org.xwiki.extension.xar.internal.doc.MandatoryDocumentInitializerListener.onEvent(MandatoryDocumentInitializerListener.java:107)
	at org.xwiki.observation.internal.DefaultObservationManager.notify(DefaultObservationManager.java:320)
	at org.xwiki.observation.internal.DefaultObservationManager.notify(DefaultObservationManager.java:285)
	at org.xwiki.component.internal.StackingComponentEventManager.sendEvent(StackingComponentEventManager.java:142)
	at org.xwiki.component.internal.StackingComponentEventManager.flushEvents(StackingComponentEventManager.java:92)
	at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.loadComponents(JarExtensionHandler.java:255)
	at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.install(JarExtensionHandler.java:183)
	at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.initialize(JarExtensionHandler.java:144)
	at org.xwiki.extension.handler.internal.DefaultExtensionHandlerManager.initialize(DefaultExtensionHandlerManager.java:154)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initializeExtensionInNamespace(DefaultExtensionInitializer.java:182)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initializeExtensionInNamespace(DefaultExtensionInitializer.java:161)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initializeExtensionDependencyInNamespace(DefaultExtensionInitializer.java:206)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initializeExtensionInNamespace(DefaultExtensionInitializer.java:177)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initializeExtensionInNamespace(DefaultExtensionInitializer.java:161)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initializeExtension(DefaultExtensionInitializer.java:127)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initialize(DefaultExtensionInitializer.java:105)
	at org.xwiki.extension.handler.internal.DefaultExtensionInitializer.initialize(DefaultExtensionInitializer.java:81)
	at org.xwiki.component.embed.InitializableLifecycleHandler.handle(InitializableLifecycleHandler.java:39)
	at org.xwiki.component.embed.EmbeddableComponentManager.createInstance(EmbeddableComponentManager.java:365)
	at org.xwiki.component.embed.EmbeddableComponentManager.getComponentInstance(EmbeddableComponentManager.java:451)
	at org.xwiki.component.embed.EmbeddableComponentManager.getInstance(EmbeddableComponentManager.java:201)
	at org.xwiki.component.embed.EmbeddableComponentManager.getInstance(EmbeddableComponentManager.java:189)
	at org.xwiki.container.servlet.XWikiServletContextListener.contextInitialized(XWikiServletContextListener.java:120)
	at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4753)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5215)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
	at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:596)
	at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1805)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.xwiki.wiki.manager.WikiManagerException: Failed to locate XWiki.XWikiServerClass documents
	at org.xwiki.wiki.internal.descriptor.document.DefaultWikiDescriptorDocumentHelper.getAllXWikiServerClassDocumentNames(DefaultWikiDescriptorDocumentHelper.java:180)
	at org.xwiki.wiki.internal.descriptor.DefaultWikiDescriptorManager.getAllIds(DefaultWikiDescriptorManager.java:104)
	... 37 common frames omitted
Caused by: org.xwiki.query.QueryException: Exception while translating [from doc.object(XWiki.XWikiServerClass) as descriptor where doc.name like 'XWikiServer%' and doc.fullName <> 'XWiki.XWikiServerClassTemplate'] XWQL query to the [hql] language. Query statement = [from doc.object(XWiki.XWikiServerClass) as descriptor where doc.name like 'XWikiServer%' and doc.fullName <> 'XWiki.XWikiServerClassTemplate']
	at org.xwiki.query.xwql.internal.XWQLQueryExecutor.execute(XWQLQueryExecutor.java:129)
	at org.xwiki.query.internal.DefaultQueryExecutorManager.execute(DefaultQueryExecutorManager.java:72)
	at org.xwiki.query.internal.DefaultQuery.execute(DefaultQuery.java:306)
	at org.xwiki.wiki.internal.descriptor.document.DefaultWikiDescriptorDocumentHelper.getAllXWikiServerClassDocumentNames(DefaultWikiDescriptorDocumentHelper.java:178)
	... 38 common frames omitted
Caused by: java.lang.NullPointerException: null
	at org.xwiki.query.xwql.internal.XWQLQueryExecutor.execute(XWQLQueryExecutor.java:88)
	... 41 common frames omitted