Same problem here, on an Asus Z170i Pro Gaming MB, i7-6700k, and Corsair LPX DDR4-3200 (2x8GB)... Will only run with one stick in. Ridiculous how often I've seen this problem posted at various tech sites.
The ram info... CMK16GX4M2B3200C16
Help...
Ncase M1 v5 | Noctua C14 HSF | nVidia 1080-FE | Corsair SF600 PS | 2 120mm Vardar's exhaust |