Assume that your organization requires user certificates for virtual private network (VPN) authentication. You try to access corporate network resources when you are connected over VPN on a Windows 8.1 Preview-based computer. In this situation, you may be prompted to re-enter your domain credentials.Note
This issue does not occur if you use smart cards for VPN authentication.
To resolve this issue, install update 2866763 from Windows Update
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
Description of the standard terminology that is used to describe Microsoft software updates