After a multitude of complaints that a recent update is causing any range of problems, including “borked” servers, an inaccessible WSUS admin console, and clients that can't contact WSUS, the Microsoft WSUS Product Team is letting customers know to delay installing KB3148812.
The update is for enabling ESD decryption provision in WSUS on Windows Server 2012 and Windows Server 2012 R2 servers. And, incidentally, this update is a required installation for syncing and distributing Windows 10 updates (feature updates) that Microsoft releases after May 1, 2016. The update also requires the April 2014 update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 (2919355) is pre-installed on Windows Server 2012 R2 servers.
As stated, Microsoft is aware of the issue and is recommending holding off until the team can deliver some additional manual steps to be taken afterward in order to realign the moving parts of the system. The extra information should be available in the same KB article yet this week.
P.S. Thanks to Mary Jo Foley for the heads-up on this one.