by Ken Task.
"definitely a problem within activities and resources"
Next then is to exclude activities and resources that are not core ... but come from one of your 100+ addons in that one troubled course?
Are these backups you are making include users - all student work if any was submitted to this course from 'hades'?
I see in another posting there is an mp4 recording - 700+ video of a meeting isn't that small considering ... and you say it doesn't finish playing? But that was one downloaded right?
Does that video play in the course itself?
More fun and games!
'SoS', Ken