Windows 10 scripted install - not working, but works by hand.

Product: Dell Inspiron 15-3552 (I know...I hate Inspirons too, but someone wanted the cheapest 15" laptops available...). No onboard Ethernet, so I use a StarTech USB31000SW USB 3.0 to Ethernet dongle

I'd like to do a scripted install of Windows 10. If I install it from the ISO by hand, it works perfectly, including recognizing the USB Ethernet dongle.

If I do a scripted install, it fails with this error:

ErrorMessage: Exception has occured in function SMPPackage.cpp() at Line No 716. Type of exception is GeneralError. Error is The filename, directory name, or volume label syntax is incorrect. Error Description is utilCSMPPackageGetMultiplesFileFromHTTP. Value of Windows error code = 6 and message is The handle is invalid.

Thoughts?

Thanks!