I created a task sequence to deploy Windows 2008 R2 via SCCM 2012 (MDT integration).
Started a virtual machine (Hyper-V) and booted via F12.

After selecting the TS the installation proceeded for about 5 minutes and then gave me the error above.

After some troubleshooting I found that the package for MDT Settings (Customsettings.ini and Unattend.xml) was incorrect (I accidentily selected MDT Package instead of Settings).

Changing the package to “MDT Settings” in the TS solved the issue.