How can I get rid of an approval request for an asset which is already deleted from CentraSite?

I cannot reject nor approve the request (eg. “ProcessApproval, Process-Not Available”), because I get the following error message:
“The user … does not have the view permission; contact the asset owner or administrator for help.”

Note: I have tried republishing the asset from WM Designer, but I get the following error:
“javax.xml.registry.UnexpectedObjectException: INMJRE0002: Expected registry objects
at com.centrasite.jaxr.LifeCycleManagerImpl.saveObjects(LifeCycleManagerImpl.java:1634)
at com.softwareag.metadata.publisher.centrasite.CentrasitePublisher.disconnectFromBackend(CentrasitePublisher.java:2438)
at com.softwareag.metadata.eclipse.publisher.framework.PublishManager.managePublish(PublishManager.java:83)
at com.webMethods.sc.solutions.ui.TitledManualPublishDialog$2.run(TitledManualPublishDialog.java:566)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)”