Not sure if this is the right fix? We've added this issue to our memory dump diagnostic which can confirm.


Consider the following scenario:

  • You have a Hyper-V host that is running Windows Server 2012 R2.

  • You run either a Windows Server 2012 or Windows Server 2012 R2 virtual machine (VM) on the Hyper-V host.

In this scenario, you receive a Stop error message that resembles the following:

STOP: 0x0000007F (parameter1, parameter2, parameter3, parameter4)


  • Stop error 0x0000007F indicates an UNEXPECTED_KERNEL_MODE_TRAP issue.

  • The parameters in this Stop error message vary depending on the configuration of the computer.

  • Not all "0x0000007F" Stop errors are caused by this issue.

This issue occurs if the following conditions are true:

  • The VM instances are part of a network load balancing (NLB) cluster, and the time-out is set in the Extended Affinity configuration.

  • The VM instances are serving traffic across the NLB cluster IP.

  • A start or drain Stop request is submitted by either VM instance.


To resolve this issue, install update 2955164. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

2955164 Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 update rollup: May 2014


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Need more help?

Expand your skills
Explore Training
Get new features first
Join Microsoft Insiders

Was this information helpful?

What affected your experience?

Thank you for your feedback!