Well, it could simply be a bug in the game; there is really no way to tell based upon your level of detail. That said, make sure you have the latest BIOS and latest graphics driver installed. I recommend that you download the latest BIOS and driver from the download center and install them manually. The download page for you NUC is here: Downloads for Intel® NUC Kit NUC6i5SYH.
Hope this helps,
I installed the latest drivers and the latest BIOS. The problem still exists.
After one of the crashes (caused by playing Mechwarrior), switching off and on, the BIOS gives a message that there is no usable boot disk.
This is the second time this message appears although the SSD is fine. (Edit: This might be a SSD problem, caused by powering the system off during operation.)
Powering up again, Windows was started.
It appears to be SSD issue based on the error message about no usable boot disk.
Were you able to load the latest graphics drivers?
Make sure your operating system has been fully updated.
I installed the latest graphics drivers (the driver version is reported as v. 18.104.22.16801 in the control panel).
It happened now 3 times that the graphics crashed/freezed while using only the firefox webbrowser (no 3D game running). Mouse cursor works for a few seconds, after that a windows bluescreen occours. After this crash the boot SSD is gone (power off and on and it is available again).
Thank you for the information.
If this is not an issue with the SSD then, I would recommend contacting Intel support for warranty options.