ORA-16473
database is not in limbo
Cause
The ALTER DATABASE SWITCHOVER TO <target_db_name> FORCE statement could not proceed because the database was in an active state.
Action
Ensure that the SWITCHOVER_STATUS column in the V$DATABASE view has the value TO PRIMARY or SESSIONS ACTIVE. If needed, start managed standby recovery and reissue the statement after the SWITCHOVER_STATUS column value changes to one of the above values.