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Looking a little closer at this it looks like its a occurring during the server shutdown:

10-Feb-2020 23:02:38.072 INFO [main] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["ajp-nio-8009"]
10-Feb-2020 23:02:38.123 INFO [main] org.apache.catalina.core.StandardService.stopInternal Stopping service Catalina
2020-02-10 23:02:40.985 ERROR [localhost-startStop-2][com_liferay_recent_documents_web:97] [com.liferay.recent.documents.web.internal.messaging.RecentDocumentsMessageListener(1950)] The deactivate method has thrown an exception 
java.lang.NullPointerException
    at com.liferay.portal.scheduler.internal.SchedulerEngineHelperImpl.lambda$unregister$0(SchedulerEngineHelperImpl.java:687)
    at java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1853)
    at com.liferay.portal.scheduler.internal.SchedulerEngineHelperImpl.unregister(SchedulerEngineHelperImpl.java:684)
    at com.liferay.recent.documents.web.internal.messaging.RecentDocumentsMessageListener.deactivate(RecentDocumentsMessageListener.java:91)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.felix.scr.impl.inject.BaseMethod.invokeMethod(BaseMethod.java:224)
    at org.apache.felix.scr.impl.inject.BaseMethod.access$500(BaseMethod.java:39)
    at org.apache.felix.scr.impl.inject.BaseMethod$Resolved.invoke(BaseMethod.java:617)
    at org.apache.felix.scr.impl.inject.BaseMethod.invoke(BaseMethod.java:501)
    at org.apache.felix.scr.impl.inject.ActivateMethod.invoke(ActivateMethod.java:302)
    at org.apache.felix.scr.impl.inject.ActivateMethod.invoke(ActivateMethod.java:294)
    at org.apache.felix.scr.impl.manager.SingleComponentManager.disposeImplementationObject(SingleComponentManager.java:343)
    at org.apache.felix.scr.impl.manager.SingleComponentManager.deleteComponent(SingleComponentManager.java:152)
    at org.apache.felix.scr.impl.manager.AbstractComponentManager.doDeactivate(AbstractComponentManager.java:813)
    at org.apache.felix.scr.impl.manager.AbstractComponentManager.deactivateInternal(AbstractComponentManager.java:787)
    at org.apache.felix.scr.impl.manager.DependencyManager.deactivateComponentManager(DependencyManager.java:2225)
    at org.apache.felix.scr.impl.manager.DependencyManager.access$500(DependencyManager.java:55)
    at org.apache.felix.scr.impl.manager.DependencyManager$SingleStaticCustomizer.removedService(DependencyManager.java:1082)
    at org.apache.felix.scr.impl.manager.DependencyManager$SingleStaticCustomizer.removedService(DependencyManager.java:968)
    at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:1241)
    at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:1136)
    at org.apache.felix.scr.impl.manager.ServiceTracker$AbstractTracked.untrack(ServiceTracker.java:996)
    at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:1175)
    at org.apache.felix.scr.impl.BundleComponentActivator$ListenerInfo.serviceChanged(BundleComponentActivator.java:127)
    at org.eclipse.osgi.internal.serviceregistry.FilteredServiceListener.serviceChanged(FilteredServiceListener.java:109)
    at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:917)
    at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
    at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEventPrivileged(ServiceRegistry.java:862)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEvent(ServiceRegistry.java:801)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.unregister(ServiceRegistrationImpl.java:222)
    at com.liferay.registry.internal.ServiceRegistrationWrapper.unregister(ServiceRegistrationWrapper.java:77)
    at com.liferay.portal.servlet.MainServlet.destroy(MainServlet.java:151)
    at org.apache.catalina.core.StandardWrapper.unload(StandardWrapper.java:1443)
    at org.apache.catalina.core.StandardWrapper.stopInternal(StandardWrapper.java:1775)
    at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:224)
    at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5465)
    at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:224)
    at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1424)
    at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1413)
    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)

I see a that a similar issue has been logged: https://issues.liferay.com/browse/LPS-96910
But i'm not so sure how closely this relates to what I'm seeing.  This is talks about the dl.file.rank.enabled being set to false.

The default value for dl.file.rank.enabled appears to be false. What exactly is this property used for? What would happen if I make it true?