In some circumstances, Word files accessed through Internet Explorer will give an error message, "File not Found".

This behaviour occurs seemingly at random, and is a function of an interaction between the Plone content management system used to run this website and Internet Explorer's handling of temporary Internet files. It seems to occur most commonly on machines running the DET Standard Operating Environment.  A solution is being sought, but is proving problematic. The behaviour does not seem to occur with alternative browsers such as Mozilla Firefox or with other types of content, such as PDFs.

Workaround
There is a simple workaround. Right-click* on the attachment being sought, and choose "Save Target As" (Internet Explorer) or "Save Link As" (Firefox). Download the file to your local computer or network. The file can then be opened without issue.

*Right-click means to use the opposite mouse button to normal. For most people, this is the right mouse button. For the gifted people who have overcome right-handedness, this will mean the left mouse button.