Version ... Site Admin Menu, Notifications.
OR from command line:
cd /path/to/moodle/code/
fgrep '$release' version.php
So all attempts to backup a course fail? Command line also?
cd /path/to/moodle/code/admin/cli/
php backup.php has help.
Probably best to save the backup to a designated directory rather than in the 'sea of files in moodledata/filedir/' so you can see them ... even un-compress them there so one can also see what might be affecting a restore.
So debugging shows nothing? either backup or restore via Web interface?
Now the nitty gritty ... do you have any documentation provided by this 'radio silent MP' concerning customizations?
Even more 'nitty gritty' ... and this might make the MP break 'radio silence' .... who is the MP?
As far as a 'fix' that anyone in community might be able to provide, community does have an 'autopilot' ... so afraid you are gonna have to provide a lot more info! :|
'SoS', Ken