I have Intel NUC6i3SYK and Ubuntu-GNOME installed on it, which is an official flavor of Ubuntu with pre-installed Gnome desktop environment. Everything else is pretty much the same as Ubuntu and the versions for both distros are released at the same time.
I bought the NUC in February and I used with Ubuntu-Gnome 15.10 (kernel 4.2.x) and the with default BIOS that it comes with 0024, all defaults.
Everything installs normally and works pretty good, until I start using some more GPU demanding tasks, at least that's my only clue. These tasks can be really trivial ones, but I noticed that with certain tasks I can get the NUC freeze (for 10 seconds) and reboot itself in no time. I'm usually running a few demos from the Chrome Experiments website that usually utilize WebGL features that heavily depend on the GPU.
The NUC is not overheating, and like I said the sudden freeze can happen in any case, but if I have only one tab open in my web browser and I don't navigate to pages containing GIFs, Video etc, I can use for hours probably.
The first suggestion found in this forum was to install the official Intel Graphics Drivers for Linux that are especially designed for Ubuntu 15.10. However that does not solved the issue, so I decided to wait for Ubuntu 16.04 LTS.
Unfortunately with Ubuntu-Gnome 16.04 LTS (kernel 4.4.x) I'm experiencing the exact same issue. Another suggestion found in this forum was to install the latest BIOS 0042, however that does not solve the issue either. The latest Ubuntu-Gnome ships with experimental support for Wayland (the little gear button on the login screen) which is somewhat newer display server protocol aimed to replace X. I heard that it have some better support for GPUs, but unfortunately the same issue appeared again.
So at this point I'm out of options, though I'm assuming it's not a hardware problem. It might not be GPU driver related either, but that's my best clue like I said.
My full configuration:
I'm attaching a picture of the bottom of the NUC for serial numbers information.
nuc-bottom-1000.jpg 185.1 K