Oracle Solution for Error ora-10456

ORA-10456: cannot open standby database; media recovery session may be in progress

What triggered the Error:

A media recovery, RMAN, or flashback database session may have been in progress on a mounted instance of a standby database when an attempt was made to open the standby database.

What should we do to fix it:

Check for and cancel any conflicting recovery session and open the standby database.