I noticed some weird behavior on our phabricator instance when I click on any attached image:

The URI changes but nothing else. I tested with differnt browsers (Chrome and Firefox) on different clients.
I also tried it with different phabricator users. And now it gets strange: If I try to shown the same image with different phabricator users ( my personal and admin) it works with the admin account.

Any Ideas? - I really don't know how to go on with the troubleshooting :(

And yes, I terminated all phabricator sessions and deleted the browser cache^^