Errors in the logs about looking up a component when installing an extension

class org.xwiki.component.manager.ComponentLookupException: Failed to lookup component [org.xwiki.ircbot.internal.XARImportEventListener] identifier by [role = [interface org.xwiki.observation.EventListener] hint = [ircxarimport]]
    at org.xwiki.component.embed.EmbeddableComponentManager.getComponentInstance(EmbeddableComponentManager.java:328)
    at org.xwiki.component.embed.EmbeddableComponentManager.getInstance(EmbeddableComponentManager.java:161)
    at org.xwiki.observation.internal.DefaultObservationManager.onEventListenerComponentAdded(DefaultObservationManager.java:316)
    at org.xwiki.observation.internal.DefaultObservationManager.onComponentEvent(DefaultObservationManager.java:294)
    at org.xwiki.observation.internal.DefaultObservationManager.notify(DefaultObservationManager.java:240)
    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:155)
    at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.install(JarExtensionHandler.java:102)
    at org.xwiki.extension.handler.internal.DefaultExtensionHandlerManager.install(DefaultExtensionHandlerManager.java:80)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.installExtension(AbstractExtensionJob.java:149)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.applyAction(AbstractExtensionJob.java:106)
    at org.xwiki.extension.job.internal.InstallJob.start(InstallJob.java:135)
    at org.xwiki.job.AbstractJob.start(AbstractJob.java:134)
    at org.xwiki.job.internal.DefaultJobManager.run(DefaultJobManager.java:156)
    at java.lang.Thread.run(Thread.java:680)
Caused by: class org.xwiki.component.manager.ComponentLookupException: Can't find descriptor for the component [role = [interface org.xwiki.model.reference.EntityReferenceSerializer] hint = [default]]
    at org.xwiki.component.embed.EmbeddableComponentManager.getComponentInstance(EmbeddableComponentManager.java:335)
    at org.xwiki.component.embed.EmbeddableComponentManager.getInstance(EmbeddableComponentManager.java:161)
    at org.xwiki.component.embed.EmbeddableComponentManager.getComponentInstance(EmbeddableComponentManager.java:333)
    at org.xwiki.component.embed.EmbeddableComponentManager.getInstance(EmbeddableComponentManager.java:161)
    at org.xwiki.component.embed.EmbeddableComponentManager.createInstance(EmbeddableComponentManager.java:292)
    at org.xwiki.component.embed.EmbeddableComponentManager.getComponentInstance(EmbeddableComponentManager.java:358)
    at org.xwiki.component.embed.EmbeddableComponentManager.getComponentInstance(EmbeddableComponentManager.java:326)
    at org.xwiki.component.embed.EmbeddableComponentManager.getInstance(EmbeddableComponentManager.java:161)
    at org.xwiki.observation.internal.DefaultObservationManager.onEventListenerComponentAdded(DefaultObservationManager.java:316)
    at org.xwiki.observation.internal.DefaultObservationManager.onComponentEvent(DefaultObservationManager.java:294)
    at org.xwiki.observation.internal.DefaultObservationManager.notify(DefaultObservationManager.java:240)
    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:155)
    at org.xwiki.extension.jar.internal.handler.JarExtensionHandler.install(JarExtensionHandler.java:102)
    at org.xwiki.extension.handler.internal.DefaultExtensionHandlerManager.install(DefaultExtensionHandlerManager.java:80)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.installExtension(AbstractExtensionJob.java:149)
    at org.xwiki.extension.job.internal.AbstractExtensionJob.applyAction(AbstractExtensionJob.java:106)
    at org.xwiki.extension.job.internal.InstallJob.start(InstallJob.java:135)
    at org.xwiki.job.AbstractJob.start(AbstractJob.java:134)
    at org.xwiki.job.internal.DefaultJobManager.run(DefaultJobManager.java:156)
    at java.lang.Thread.run(Thread.java:680)