After installing the Azure sdk 1.6 on my SharePoint box, I faced a set of annoying problems like the BCS, the UPS, the MMS that didn’t work anymore.
The procedure to fix this problem is described in the following post of Christian Glessner :
To summarize, type the following Powershell instructions :
PS>set-webconfigurationproperty /system.webServer/security/authentication/anonymousAuthentication -name userName -value "IUSR"
Thank you Christian and Wictor Wilen.