Hi everyone,
Last week, Microsoft has released some update concerning Windows Server 2008 R2.Precision : Our Operating System are in french.
After these updates (and I suspect that the error comes from KB3074550), on all of the Domain Controller (we have 2 Active Directory production and one for test and 3 Domain Controller in each), there is now an error with the GPO : Collecting data for Administrative Templates :(just to insist, the OS are in french) :Une erreur s’est produite lors de la lecture des données pour Modèles d’administration.
Les erreurs suivantes se sont produites :

La ressource « $(string.SiteDiscoveryEnableWMI) » référencée dans l’attribut displayName est introuvable. Fichier C:\Windows\PolicyDefinitions\inetres.admx, ligne 34686, colonne 235I think it could be translated in English by :An error has occurred while collecting data for Administrative Templates. The following errors were encountered: Resource ‘$(string.SiteDiscoveryEnableWMI)’ referenced in attribute displayName could not be found. File C:\Windows\PolicyDefinitions\inetres.admx, line 34686, column 235

After googling, it seems that the solution could be simple :
Download the Administrative Templates from Microsoft’s website – http://www.microsoft.com/en-US/download/details.aspx?id=41193
Extract the files on your domain controller in C:\Windows\SYSVOL\domain\Policies folder (it will create a folder called PolicyDefinitions)
Nevertheless, I woul really appreciate your comments on this situation before doing this operation.
Thanks in advance !