Unable to Start Output Post Processor and workflow related Concurrent Manager

Error in logfile :
$ cat FNDOPP10587566924.txt
Unable to initialize state monitor.
oracle.apps.fnd.cp.gsm.GenCartCommException: ORA-01403: no data found
ORA-06512: at “APPS.FND_CP_GSM_IPC”, line 539
ORA-06512: at line 1
at oracl.apps.fnd.cp.gsm.GenCartComm.initService(GenCartComm.java:233)
at oracle.apps.fnd.cp.gsm.GenCartComm.(GenCartComm.java:80)
at oracle.apps.fnd.cp.gsf.GSMStateMonitor.init(GSMStateMonitor.java:74)
at oracle.apps.fnd.cp.gsf.GSMStateMonitor.(GSMStateMonitor.java:62)
at oracle.apps.fnd.cp.gsf.GSMServiceController.init(GSMServiceController.java:117)
at oracle.apps.fnd.cp.gsf.GSMServiceController.(GSMServiceController.java:72)
at oracle.apps.fnd.cp.gsf.GSMServiceController.main(GSMServiceController.java:446)
0.0128720 secs]
$
Similar errors are present in workflow concurrent manager.
These errors generally comes if the Service Manager (FNDSM)  is not up or if it is up,it is hang situation.
This can happen in Concurrent Manager failover or failback in Parallel concurrent Processing env.
If FNDSM is not Up,  we can activate and deactivate Internal monitor, it will automatically bring up the FNDSM
if FNDSM is hang, then kill the process using the below process
ps -ef|grep FNDSM
kill -9 <pid>
and then we can activate and deactivate Internal monitor, it will automatically bring up the FNDSM
Why we saying here Internal monitor as it is safe to restart the process any time with out stopping any crfitical buisness process
Once FNDSM is up, workflow related manager and Output post processor will come automatically. Hope this resolve the Unable to Start Output Post Processor in your environment also
We can look up at Concurrent Manager concept in below articles.