Workflow process is not getting deleted from Process Administrator in Windchill PDMLink

YYYY-MM-DD  INFO  [XXXX] wt.system.out SEwcadmin - wt.util.WTRuntimeException: Cannot restore "wt.workflow.engine.WfRequesterActivity.XXXXX" because it no longer exists. Nested exception is:
YYYY-MM-DD  INFO  [YYYY] wt.system.out SEwcadmin - 	(wt.fc.fcResource/32) wt.fc.ObjectNoLongerExistsException: Cannot restore "wt.workflow.engine.WfRequesterActivity.XXXXX" because it no longer exists.
YYYY-MM-DD  ERROR [ZZZZ] wt.pds.exception SEwcadmin - Unable to perform delete for 1 records wt.util.WTException: wt.util.WTRuntimeException: Cannot restore "wt.workflow.engine.WfRequesterActivity.XXXXX" because it no longer exists. Nested exception is:
	(wt.fc.fcResource/32) wt.fc.ObjectNoLongerExistsException: Cannot restore "wt.workflow.engine.WfRequesterActivity.XXXXX" because it no longer exists.
Nested exception is: wt.util.WTRuntimeException: Cannot restore "wt.workflow.engine.WfRequesterActivity.XXXXX" because it no longer exists. Nested exception is:
	(wt.fc.fcResource/32) wt.fc.ObjectNoLongerExistsException: Cannot restore "wt.workflow.engine.WfRequesterActivity.XXXXX" because it no longer exists.
	at wt.fc.StandardPersistenceManager.restore(StandardPersistenceManager.java:1954)
	at wt.fc.StandardPersistenceManager.refresh(StandardPersistenceManager.java:1075)
	at wt.fc.StandardPersistenceManager.refresh(StandardPersistenceManager.java:500)
	at jdk.internal.reflect.GeneratedMethodAccessor55.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at wt.services.ServiceFactory$ServerInvocationHandler.invoke(ServiceFactory.java:399)
	at com.sun.proxy.$Proxy29.refresh(Unknown Source)
	at wt.fc.DefaultInflator$OidCache.inflate(DefaultInflator.java:383)
	at wt.fc.DefaultInflator$OidCache.inflate(DefaultInflator.java:375)
	at wt.fc.DefaultInflator$AbstractCache.get(DefaultInflator.java:291)
	at wt.fc.DefaultInflator$AbstractCache.get(DefaultInflator.java:259)
	at wt.fc.DefaultInflator.get(DefaultInflator.java:153)
	at wt.fc.ObjectReference.getObject(ObjectReference.java:735)
	at wt.workflow.engine.WfBlock.getParentProcess(WfBlock.java:513)
	at wt.workflow.engine.WfActivity.getParentProcess(WfActivity.java:772)
	at wt.workflow.robots.WfSynchRobot.getContext(WfSynchRobot.java:753)
	at wt.workflow.robots.WfSynchRobot.deleteSubscriptions(WfSynchRobot.java:1008)
	at wt.workflow.engine.StandardWfEngineService.deleteContainedObjects(StandardWfEngineService.java:8357)
	at wt.workflow.engine.StandardWfEngineService.deleteContainedObjects(StandardWfEngineService.java:8448)
	at wt.workflow.engine.StandardWfEngineService$2.notifyVetoableMultiObjectEvent(StandardWfEngineService.java:9811)
	at wt.events.StandardKeyedEventBranch.intDispatchEvent(StandardKeyedEventBranch.java:306)
	at wt.events.StandardKeyedEventBranch.dispatchVetoableMultiObjectEvent(StandardKeyedEventBranch.java:268)
	at wt.events.StandardKeyedEventDispatcher.intDispatchEvent(StandardKeyedEventDispatcher.java:306)
	at wt.events.StandardKeyedEventDispatcher.dispatchVetoableMultiObjectEvent(StandardKeyedEventDispatcher.java:244)
	at wt.services.StandardManagerService.intDispatchVetoableEvent(StandardManagerService.java:412)
	at wt.services.StandardManagerService.dispatchVetoableMultiObjectEvent(StandardManagerService.java:314)
	at wt.fc.StandardPersistenceManager.dispatchVetoableEvent(StandardPersistenceManager.java:3012)
	at wt.fc.StandardPersistenceManager.dispatchVetoableEvent(StandardPersistenceManager.java:2995)
	at wt.fc.StandardPersistenceManager.delete(StandardPersistenceManager.java:802)
	at wt.fc.StandardPersistenceManager.delete(StandardPersistenceManager.java:383)
	at jdk.internal.reflect.GeneratedMethodAccessor1242.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at wt.services.ServiceFactory$ServerInvocationHandler.invoke(ServiceFactory.java:399)
	at com.sun.proxy.$Proxy29.delete(Unknown Source)
	at wt.workflow.engine.StandardWfEngineService.deleteProcess(StandardWfEngineService.java:4396)
	at jdk.internal.reflect.GeneratedMethodAccessor1319.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at wt.services.ServiceFactory$ServerInvocationHandler.invoke(ServiceFactory.java:399)
	at com.sun.proxy.$Proxy301.deleteProcess(Unknown Source)
	at com.ptc.netmarkets.workflow.NmWorkflowCommands.delete(NmWorkflowCommands.java:717)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at com.ptc.core.components.forms.FormDispatcher.callWizardCommand(FormDispatcher.java:112)
	at com.ptc.core.components.forms.FormDispatcher.execute(FormDispatcher.java:98)
	at jdk.internal.reflect.GeneratedMethodAccessor1027.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at com.ptc.netmarkets.util.beans.NmCommandBean.execute(NmCommandBean.java:2247)
	at com.ptc.jca.mvc.controllers.ActionController.executeWizardAction(ActionController.java:222)
	at com.ptc.jca.mvc.controllers.ActionController.processRequest(ActionController.java:125)
	at jdk.internal.reflect.GeneratedMethodAccessor1026.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1072)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:965)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:515)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:583)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:212)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156)
	at wt.licenseusage.licensing.LicenseFilter.doFilter(LicenseFilter.java:47)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156)
	at com.ptc.core.ui.validation.URLValidationFilter.doFilter(URLValidationFilter.java:86)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156)
	at wt.httpgw.filter.WTContextBeanFilter.doWithWtContextBeanHandler(WTContextBeanFilter.java:104)
	at wt.httpgw.filter.WTContextBeanFilter.doFilter(WTContextBeanFilter.java:58)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156)
	at wt.servlet.CompressionFilter.doFilter(CompressionFilter.java:301)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156)
	at wt.servlet.RequestInterrupter.doFilter(RequestInterrupter.java:335)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156)
	at wt.servlet.ServletRequestMonitor.doFilter(ServletRequestMonitor.java:1677)
	at wt.servlet.ServletRequestMonitorFilter.doFilter(ServletRequestMonitorFilter.java:57)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:483)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
	at org.apache.coyote.ajp.AjpProcessor.service(AjpProcessor.java:533)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:932)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1705)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.base/java.lang.Thread.run(Thread.java:829)