I successfully upload a Word file for my bug. I click the attachment's file name to open it, but nothing comes out. I have to save the attachment file first, and then open it. I am using Word2000, and Mantis 0.19.0. Thanks for help.
Are you using IE 6? If so, there is an issue with the no-cache header we send. It doesn't seem to allow the browser to copy the file after uploading it because of the strict interpretation of no-cache. I believe that we fixed this in 1.0.0.