Microsoft has released new rollup for Server 2012 R2. This update resolves plenty issues and bugs:
2958293 Cluster service stops unexpectedly on Windows 8.1 or Windows Server 2012 R2
2958264 The virtual machine freezes in “Turning Off” state during live migration in Windows 8.1 or Windows Server 2012 R2
2957625 Cluster shared volumes (CSV) are stuck when you stop a cluster service in Windows Server 2012 R2
2908783 Data corruption occurs on iSCSI LUNs in Windows
2957018 VMMS.exe process crashes after restart on a Windows 8.1 or Windows Server 2012 R2-based Hyper-V cluster
2955628 Nodes are broken in cluster RHS upon file backchannel invalidation in Windows Server 2012 R2
The main prerequisite: installed 2919355 Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 Update April, 2014.
More information: KB2955164
Highly recommended to apply.
IMPORTANT: this update changes QFE level from 6.3.163xx to 6.3.17xxx . It may affect the Microsoft DSM version and your cluster validation results. If you receive “QFE Number is not the same on every nodes.” , you have to check updates or see my article