This is the same type of error -- caused by multiple file names that are the same.
I guessed at what they should be and changed them, but that generated a different error code, so I changed them back, and all of a sudden the page is not generating an error code any more. I tried downloading a file just to make sure it worked, and it did.
Don't know what I did but it seems to have kickstarted the correct behaviour.
[Edit] Just tried this with the Hotteterre -- naming to different (wrong) name, then naming it back to original (duplicated) name. Now this page works as well. Bizarre behaviour, but as long as it works . . .