You try to use a command on the ribbon, but the command is disabled or unavailable.
The file you have opened is rights-managed using Information Rights Management technology and you do not have permission to forward, copy, modify, print, or fax the file. As a result, commands that would otherwise allow you to perform those functions have been disabled.
Other possible causes are:
Commands are disabled by the administrator
The file is in Reduced Functionality Mode
The file opened in Protected View
You should contact the owner of the rights-managed file to see if you can be granted less restricted permissions to the file. For more information, see Information Rights Management in Office 2010.