The Bootwiz log will show you why it failed, but yes, we've seen that. Make sure you are up on the latest HF. Do NOT skimp on that. The fixes coming out are critical. For instance, DA driver injection took a MAJOR lift in HF5.
That said, if you can see the folders, don't worry about if it "finished" in the console or not. Just run a rebuild of the preboot.
You may want to become familiar with the Bootwiz log anyway though, as we HAVE occasionally seen issues with DISM not compiling in the drivers that are in that folder.
Important: The folders are created.
Not Important: The console screen finishes.
Important: The drivers are compiled into the preboot.
And remember that just because BW finishes means nothing. If DISM fails to compile the driver, BW continues on and finishes "successfully" anyway.
Soooo, just rebuild and see if it works. GL!