Usually, the OP Backup is set to copy the backup file to an external hard drive. Often times, this process fails because the hard drive either wasn't plugged in at all or the computer no longer recognizes that the drive is plugged in. This does not mean that your backup failed, just that the file wasn't copied to the other drive. Unplug and plug in the external drive, then open My Computer to make sure that the external drive is recognized.
The copy can also fail if the path is not recognized, meaning the hard drive is plugged in, but it is expecting to find the folder BAKMED and BAKDOC on the drive and those folders do not exist. If this occurs, click the hard drive and add the new folders. If you are not comfortable with this process, you can contact OP or your practice's IT person.