Fatal error: Class 'WP_List_Table' not found in /home/XYZ/public_html/wp-content/plugins/backwpup/app/list-tables.php on line 10
I havn't looked into this much. Thought I'd post it and see if it makes sense to a programmer before I start going into it in more detail
the WP build is nov 22nd. Sorry I can't be more definitive about that.