With the latest update to Acrobat to 10.1.3 a problem arose with viewing attached PDFs. It was observed widely by users of browsers such as Firefox. I'm seeing an identical problem in Zimbra Desktop.
The Download link actually works for me but this doesn't help when I want to preview an attachment that I have attached to a message I am composing prior to hitting the Send button.
The fix in the Firefox browser is to run in 32-bit mode (via Finder -> Applications -> right-click Firefox -> Get Info -> check Open in 32-bit mode). This fixed the issure for me in the Zimbra web client.
Is there a similar fix for Zimbra Desktop?