This issue occurs when the following conditions are true:
You run a Cisco AnyConnect Secure Mobility Client application to establish virtual private network (VPN) connections in Windows 8.1, Windows RT 8.1, or Windows Server 2012 R2.
You have installed update 3023607 on the computer. For more information about update 3023607, see the Secure Channel cumulative update changes TLS protocol renegotiation and fallback behavior.
To resolve this issue, go to Microsoft Update.
The Microsoft Update will help you install March cumulative security update for Internet Explorer (MS15-018) or Vulnerability in SChannel could allow security feature bypass: March 10, 2015 (MS15-031). If you download and install updates manually, refer to the Affected Software table in Microsoft Security Bulletin MS15-018 for download links.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
See the terminology that Microsoft uses to describe software updates.
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.