Word 2013 gives an error when opening a file downloaded from the web

Today, after downloading an important attachment from my Gmail Account, I got the following error while trying to open it:

Word experienced an error trying to open the file.
Try these suggestions:
*Check the file permissions for the document or drive.
*Make sure there is sufficient free memory and disk space
*Open the file with the Text Recovery converter.

The solution is to right click the file then on the properties box click unblock.