Ideas after you config file. And what GPU model?
sgminer.exe -k x16r -o stratum+tcp://us.ravenminer.com:5678 -u myrvnwallet -p worker1 -X 256 (also tried -X 64 same result)
This is a fresh Win10 install updated, redist installed, blockchain drivers XFX Core Black RX580 brand new out of the box with stock bios, installed in the pcie 16x slot...
1st. add
--log-file log-x16r.txt
after -X256 and look inside when starting miner.
2nd. the miner must compile a kernel for you GPU its may be more than 2-3 minutes up to 5. see log-x16r.txt
3rd. try without -X256.
And why you use blockchain drivers? it's does not matter but why? new adrenalin drivers is good performance and more flexible with playing with voltage and overclocks(for me).