When attempting to use the Access Utility via SCCM or other deployment tool via command line, you may receive an Access Denied error when attempting to access the drive after successful authentication.
An issue has been identified with WinPE 3.0 and is currently being addressed which prevents access to the disc as expected. Instead of building your boot image with WinPE 3.0, a previous version of PE can be used as an alternative.
Build the boot.wim with WinPE 2.1 instead of 3.0. This issue has been reported to engineering and is currently under investigation.