DTOO189 - Office System - The encryption type for password protected Open XML files must be set.
If unencrypted files are intercepted, sensitive information in the files can be compromised. To protect information confidentiality, Office application files can be encrypted and password protected. Only users who know the correct password will be able to decrypt such files.
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Office 2010 -> Security Settings 'Encryption type for password protected Office Open XML files' to 'Enabled (Microsoft Enhanced RSA and AES Cryptographic Provider,AES 256,256)'.