It looks like all downloads that have a question mark in the download link are broken.
For example, see here:
If you hover over the linked title on that page, you'll see the actual download link embedded in there: http://apolyton.net/upload/view.php?file=10252_Civ2Booklet.zip
(note the question mark in the URL there)
But when you then actually click on the link, you're forwarded to:
... and get to see the message "File doesnt exist."
Manually removing the %3f makes it work again.
This happens with all download links with question marks in them (as far as I've tested). They get the %3f appended to the end of them. Note that %3f happens to be the URL encoded version of a question mark...
Could you please fix this?