Same for me, as I have written a few pages back in this topic...
Try this one as I have also written in my quoted text(maybe try replacing 1 with 0):
sgminer.exe --gpu-platform 1 -n

yes. it worked and I see my cards..
sig-miner>sgminer.exe --gpu-platform 1 -n
[00:08:06] CL Platform vendor: NVIDIA Corporation
[00:08:06] CL Platform name: NVIDIA CUDA
[00:08:06] CL Platform version: OpenCL 1.2 CUDA 8.0.0
[00:08:06] Platform devices: 6
[00:08:06] 0 GeForce GTX 1070
[00:08:06] 1 GeForce GTX 1070
[00:08:06] 2 GeForce GTX 1070
[00:08:06] 3 GeForce GTX 1070
[00:08:06] 4 GeForce GTX 1070
[00:08:06] 5 GeForce GTX 1070
[00:08:06] Unable to load the AMD Display Library
[00:08:06] 6 GPU devices max detected
but sgminer dosnt start
sgminer.exe -k skunkhash --gpu-platform 1 -v -o stratum+tcp://pool.hashbag.cc:8644 -u adddressss -p c=SIGT
just see on screen
[23:56:32] Started sgminer 5.3.3
[23:56:32] * using Jansson 2.10
no mining...
add -d 0, -d 0-5 - dosnt help
try with:
sgminer.exe -k skunkhash --gpu-platform 0 -o stratum+tcp://pool.hashbag.cc:8644 -u adddressss -p c=SIGT -I 18 --verbose
Anyway you'll have no output except "Started sgminer 5.3.3" until it actually starts mining. Or you can change the code and rebuild the miner for the full output instead of starting text.