Attachments give 404

I don’t know why I didn’t notice this before, but…

The dhandler in /Ticket/Attachment doesn’t seem to be
functioning inside my 2.0.13 RT release.

If you click on an attachment in a ticket display, the
error is just 404 file not found.

Is there something else I need to do mason-wise to get this
working? I can’t seem to find anything else broken.

As near as I can tell, permissions/ownerships are right, but
not absolutely positive.