Windows could not parse or process the unattend answer file for pass [specialize]

I was at a customer which I have deployed vCloud Automation Center 6.1 for, and they tried to create a new blueprint. They have copied the old blueprint and only changed the VM template used in that blueprint from Windows 2012 to Windows 2008 R2. They saved and published the new blueprint without any problem, then they tried to deploy the new blueprint. The blueprint deployment kept failing with the following error:

“Request failed: Machine VTTestVM001: Timeout customizing machine”

From the error, I was able to tell it was getting stuck at the guest customization stage, so I deployed one more VM and waited till it get to the guest customization stage, then opened a console to the VM to be greeted  with the following Sysprep error:

Windows could not parse or process the unattend answer file for pass [specialize]. The settings specified in the answer file cannot be applied. The error was detected while processing settings for component [Microsoft-Windows-Shell-Setup]”

Below is a screenshot showing the actual error on screen:

Windows could not parse or process the unattend answer file or pass [specialize]

After I hit OK, the machine restarted again and gave the following error and kept repetitively restarting and giving the same error afterword:

“The computer restarted unexpectedly or encountered an unexpected error.Read More