Oracle Error Message
ORA-19565: BACKUP_TAPE_IO_SLAVES not enabled when duplexing to sequential devices
Reason for the Error
An attempt was made to specify duplexing to sequential devices, but the BACKUP_TAPE_IO_SLAVES initialization parameter was not enabled.
Solution
Specify BACKUP_TAPE_IO_SLAVES=TRUE in the INIT.ORA file, or do not specify duplexing to sequential devices.