I did a upgrade of my Phabrictor to the new stable version and since then I see that the paths in Diffusion are shown absolute, which breaks file browsing.
I can see the same behavior also on https://secure.phabricator.com so it seems to be a general issue. Screenshots are from https://secure.phabricator.com:
The URL looks for this file
Correcting the URL to
shows the right content.