I have a XDP file that Acrobat can open. It contains a PDF plus some data to fill in the form fields in the PDF.
In my HTTP request header I set
content-typ
I wonder if this open source project will solve your web display problem: pdf.js If not immediately, perhaps you can help it along.
It looks like an administration problem. Your file is being downloaded but Adobe doesn't have the access rights to that folder.
Contact your network administrator is my only answer.