New data blocks initialize incorrectly when a differencing VHD is expanded in Windows

Symptoms

This issue occurs if you use the CreateVirtualDisk parameter to create a disk by expanding from a parent virtual hard disk (VHD). When you do this, you set the ParentPath parameter to a non-null value and set the MaximumSize parameter to a value that is larger than the parent disk size. In this situation, the expanded VHD is corrupted in Windows 8.1, Windows Server 2012 R2, Windows 8, or Windows Server 2012.

Resolution

To resolve this issue, install the update rollup that is dated December 2014.

• Get the December 2014 update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2

• Get the December 2014 update rollup for Windows RT, Windows 8, and Windows Server 2012

Status

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

More Information

See the terminology that Microsoft uses to describe software updates.