On Friday, October 17 Microsoft revised the 2949927 advisory with the following statement:
Removed Download Center links for Microsoft security update 2949927. Microsoft recommends that customers experiencing issues uninstall this update. Microsoft is investigating behavior associated with this update, and will update the advisory when more information becomes available.
The second proactive update (2977292) enhanced the Microsoft Extensible Authentication Protocol (EAP) implementation in several versions of Windows by enabling the use of Transport Layer Security (TLS) 1.1 or 1.2. The third (2871997) adds a restricted admin mode for Remote Desktop Connection and Remote Desktop Protocol.
Stability problems with other October Microsoft updates were mentioned in a sardonic InfoWorld story. Microsoft hasn't commented publicly on problems in other updates.