ORA-16918
Standby pluggable database is not ready after previous role change.
Cause
The standby pluggable database is not recovering redo data from the new source pluggable database after a previous switchover or reinstate operation.
Action
See accompanying messages for more information. If necessary, start Redo Apply services by issuing the DGMGRL command EDIT PLUGGABLE DATABASE name SET STATE=APPLY-ON.