I would advise testing the system with minimum components and BIOS settings reset to default. Some of these errors may be caused by software conflict, from antivirus or such. You may also want to check if the SSD and other peripherals have the latest firmware.
Try getting a minidump file from Windows* after the event occurs. This may provide additional information.
@joe_intel: Thanks for the reply.
Crucial SSD has firmware MU05 from 3/2014 (Latest). No antivirus currently running (disabled Windows Defender when I started troubleshooting). I have some Minidumps and Kernel dumps that I've been collecting. Some seem to implicate Intel drivers. Would you be able to help analyze? I'll try resetting BIOS setting, using a different keyboard/mouse and report back today or tomorrow.
@spinlock123: I also suspect the RAM, even though it passes MemTest86+. I may order some new RAM (CL10 or 11) and try that and report back when it arrives.
Hey guys, I solved the issue. I RMA'd the Kingston KHX16LS9P1K2/16 (CL9 16GB RAM). Kingston sent me a new / updated version of the kit. It's still 16GB/CL9, but it's a slightly different color and model number. Windows 8.1 has been running stable for weeks now on the NUC.
Turned out to be faulty or incompatible RAM after all.