The Windows Team has released update KB3159706 that enables the provisioning of decryption keys in WSUS for Windows Server 2012 and 2012 R2. This update is necessary for WSUS to be able to natively decrypt the encrypted Windows 10 Anniversary Update packages, and any subsequent Windows 10 feature upgrades. Additionally, the 1606 update for the current branch of Configuration Manger contains new client support that allows these types of packages to install correctly using the Configuration Manager Windows 10 servicing feature.
Both updates are needed for the ConfigMgr Windows 10 servicing feature to deploy Windows 10 feature upgrades starting with the Windows 10 Anniversary Update. We recommend that you install KB3159706 on your Software Update Point (SUP) servers following the required manual installation steps that are outlined in the kb article before starting deployments of the Windows 10 Anniversary Update.
Until your SUP servers are updated, you can use the ConfigMgr Operating System Deployment (OSD) feature as an alternative to the SUM/Windows 10 servicing feature to deploy the Windows 10 Anniversary Update.
Read the WSUS team blog post – The long-term fix for KB3148812 issues