Hi Tom, we have the problem with the attachments for a longer time now. They don't work.
I tried pdf, gif, doc and jpg – always the same error. Perhaps the firewall of your servers or any other safety program is blocking? Or do you have something to change in the configuration, e.g. “enable attachment”?
I remember, when I started here (almost 2 years ago) it was possible, but just few weeks later it didn't work. What I am recognizing, after you have chosen the upload file, the post is ready. Usually you see the upload working – so probably the settings or a main error in the software is the problem.