It means that the schedule cannot write back the success or other data to the CRD database.
MY CRD database is stored in a sql server off site. I get this error every time there is a comunication failure in the ODBC connection e.g. when the vpn is down. I have set my schedules to "retry 100 times" so the schedule keeps retrying until communications are back up again. Then the schedules run without error.
