A) Verify that the 3 deleted files (backuplib.php, lib.php and restorelib.php) and the deleted dir (bb) aren't any more present under /backup. B) Perform the following operations and verify nothing fails about (lib|backuplib|restorelib) stuff: Backup a course. Restore a course. Import contents from a course from another. Duplicate an activity. Enable automated backups (admin->courses->backup->automated", setting it to manual and perform an execution of admin/cli/automated_backups.php with web server credentials). Verify that the "backup" admin report works without error. And show the results of the last execution. It doesn't matter if the status of any course is failed or unfinished or if that date is January 1970. Unrelated to this issue. Create a book activity and export it using the "Generate IMS CP" option (activity administration block). It should lead to the generation & download of a .zip file containing an imsmanifest.xml file. Open it with any editor and verify it looks ok and does not contain any PHP error.