500 Internal Server Error

[DatastreamManagedContent] returned the error: "org.fcrepo.server.errors.ObjectNotInLowlevelStorageException". Reason: no path in db registry for [uk-ac-man-scw:84016+POST-PEER-REVIEW-NON-PUBLISHERS.PDF+POST-PEER-REVIEW-NON-PUBLISHERS.PDF.0]

org.fcrepo.server.errors.StreamIOException: [DatastreamManagedContent] returned  the error: "org.fcrepo.server.errors.ObjectNotInLowlevelStorageException". Reason: no path in db registry for [uk-ac-man-scw:84016+POST-PEER-REVIEW-NON-PUBLISHERS.PDF+POST-PEER-REVIEW-NON-PUBLISHERS.PDF.0]
	at org.fcrepo.server.storage.types.DatastreamManagedContent.getContentSize(DatastreamManagedContent.java:259)
	at org.fcrepo.server.access.DefaultAccess.getDatastreamDissemination(DefaultAccess.java:1129)
	at org.fcrepo.server.access.FedoraAccessServlet.getDatastreamDissemination(FedoraAccessServlet.java:594)
	at org.fcrepo.server.access.FedoraAccessServlet.doGet(FedoraAccessServlet.java:447)
	at org.fcrepo.server.access.FedoraAccessServlet.doPost(FedoraAccessServlet.java:911)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
	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.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:369)
	at org.fcrepo.server.security.jaas.AuthFilterJAAS.doFilter(AuthFilterJAAS.java:329)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
	at org.springframework.security.web.access.channel.ChannelProcessingFilter.doFilter(ChannelProcessingFilter.java:109)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:168)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:617)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1521)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1478)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.fcrepo.server.errors.ObjectNotInLowlevelStorageException: no path in db registry for [uk-ac-man-scw:84016+POST-PEER-REVIEW-NON-PUBLISHERS.PDF+POST-PEER-REVIEW-NON-PUBLISHERS.PDF.0]
	at org.fcrepo.server.storage.lowlevel.DBPathRegistry.get(DBPathRegistry.java:129)
	at org.fcrepo.server.storage.lowlevel.defaultstore.Store.getFile(Store.java:177)
	at org.fcrepo.server.storage.lowlevel.defaultstore.Store.getSize(Store.java:150)
	at org.fcrepo.server.storage.lowlevel.DefaultLowlevelStorage.getDatastreamSize(DefaultLowlevelStorage.java:152)
	at org.fcrepo.server.storage.lowlevel.DefaultLowlevelStorageModule.getDatastreamSize(DefaultLowlevelStorageModule.java:189)
	at org.fcrepo.server.storage.types.DatastreamManagedContent.getContentSize(DatastreamManagedContent.java:230)
	... 37 more