Backup in 2.6 and restore to 2.4 - Error

Hi,

I need to backup a number of courses that are currently hosted on a 2.6 installation of moodle, and then restore these into a separate instance of moodle running 2.4

I keep getting the error when restoring 'error/tmp_backup_directory_not_found' after first clicking Restore.I have tried unticking all items on the backup so only the topics are restored, in case any of the blocks/activities etc were causing the error, but this still results in the same message.

Any help is would be great.