Troubleshooting seemed to help - had few changes I could make other than delete the .ini and validate on Steam. Turns out one file was incorrect so DX12 loaded fine for me after (and benchmark showed enormous performance gains from DX11). Thanks!
Hi there, Thought I would add that on my single card setup, I have a similar issue (bought the game today). I hit the initial loading screen on DX12 but it never gets past there and I have to CTRL+ALT+DEL or hard reset. DX11 I can open and run the benchmark (haven't tried play yet) but DX12 is a no go. Running an i5 2500k (4.5 GHz), R9 290 (Sapphire Tri X, lightly OCed), 8 GB 1600 MHz RAM. Thanks!