Windows 10 deployments fail with Microsoft Deployment Toolkit on computers with BIOS type firmware

Symptoms

Windows 10 deployments using the Microsoft Deployment Toolkit (MDT) build 8456 fail when used with the Windows Assessment and Deployment Kit (ADK) for Windows 10, version 2004.
The BIOS firmware type is incorrectly identified as UEFI resulting in failures when refreshing an existing computer with a new version of Windows.
When this issue occurs, the smsts.log will record the following entry:
UEFI: true
Errors resembling the following are then recorded at the end of the process.

Marking partitions active is only supported for MBR disks.
Unable to activate partition (0x80004001)
Failed to make volume C:\ bootable. Code 0x80004001.
Failed to make volume C:\ bootable. Please ensure that you have set an active partition on the boot disk before installing the operating system. Not implemented (Error: 80004001; Source: Windows)
Process completed with exit code 2147500033
Failed to run the action: Apply Operating System. Error -2147467263

You may also see the following logged in Deployment Summary

Failure (5616) 15299 Verify BCDBootEx
LiteTouch deployment failed, Return Code = 2147467259 0x80004005
Failed to run the action:  Install Operating system
Unknown error (error: 000015F0, Source:  Unknown)

Resolution

Microsoft Download Centre

The following update to resolve this problem is available for download from the Microsoft Download Center:

Download this update now.

After you download and extract the contents of the self-extracting compressed file, MDT_KB4564442.exe, use the following steps to replace the original files on any affected computers with the Microsoft Deployment Toolkit installed.

1. Close the Deployment Workbench.
2. Backup the existing x86 and x64 versions of the Microsoft.BDD.Utility.dll file in the following locations.
   %ProgramFiles%\Microsoft Deployment Toolkit\Templates\Distribution\Tools\x86\
   %ProgramFiles%\Microsoft Deployment Toolkit\Templates\Distribution\Tools\x64\
3. Copy the new files extracted from MDT_KB4564442.exe over the old versions.
4. For each deployment share that you have created, repeat the file replacement (e.g. C:\DeploymentShare\Tools\x86, C:\DeploymentShare\Tools\x64, etc.).
5. Open the Deployment Workbench, select the Deployment Share and choose the Update Deployment Share option, choosing to completely regenerate the boot image.  Perform this step for each deployment share to ensure each one is updated with the correct binaries.

Prerequisites

This update is only intended for computers with the Microsoft Deployment Toolkit build 8456 installed.
Earlier versions of Microsoft Deployment Toolkit do not support Windows Assessment and Deployment Kit (ADK) for Windows 10, version 2004.