I believed lots of persons facing this kind of problem with USB3.0 external storage/harddisk.
When you start the pc, the system will freeze or prompt up some message. Then you are unable to start or need to unplug the USB3.0 devices.
After i searched lots of Google answer and my testing,, the simple way to solve it...
Go to Bios:-
Disable all "tick" and make it disable.
Your NUC will start and read your Msata only........make sure you set your msata as first priority also.
Hope above suggestion will help you.