OCI-11418
the source CDB has purged its copy of the control file
Cause
Recovery attempted to move into the next lifespan for a per PDB Data Guard (DGPDB) but the source conatiner database (CDB) had purged the copy of the control file that it created at the time it became the source for this DGPDB.
Action
Recovery can not proceed. The DGPDB must be dropped and if required a new one instantiated from the current source. This situation only happens when recovery is stopped for a long period of time. Ensure recovery is run regularly to prevent there becoming such a long lag between where apply has got to and when a switchover is performed.