Was downloading some of the revised presentations and noticed that several links are broken.
They are 6C-2684, 6C-2690, 7-1620, 7-1920, 7-2795, 7-2859, 8-2581, 10-2529, 11-2552, 1a-2879, 3-2614, 6B-2402,
It looks like the issue is that the title is too long for most except for 11-2552 which is a zero sized file.