I first bought wrong error with 1,5V and this of course didn't work. Now I received new memory Kingston 4gb so-dimm 1600mhz ddr3l cl11 ecc 1.35v (KVR16LSE11/4), and this doesn't work either. Blinks repeatedly 3 times on startup. Isn't this memory supposed to work? Might there be something wrong with the NUC, or have I managed to buy wrong error for second time now. Confusing!
It's likely that the ECC feature of the second memory you purchased is the problem. The Intel NUCs support only non-ECC memory.
You can view a list of tested memory for this NUC at http://support.intel.com/support/motherboards/desktop/sb/CS-034586.htm.