Windows 2008 R2 SP1 Datacenter with Hyper-V role installed. OS on drive C. Hyper-V configured to store everything on drive D.
Created a snapshot of a VM prior to installing software update on VM.
Update was successful.
Shut down VM, then in Hyper-V Manager attempt to either Delete snapshot subtree or Delete Snapshot in order to merge.
Get failure message:
An error occurred while attempting to delete the selected snapshot subtree.
<server> failed to remove snapshot.
Have restarted machine and VMMS.
Nothing else I can find online to resolve this.
Rick