If you can, post a Log of the crash (Help > Logging).
I'm thinking it is related to your audio setup, so perhaps we can try to solve that problem (since you want the audio-for-video set up separately from audio-for-music anyway).
1. Make a new Zone for Video purposes. Player > Zones > Add new zone.
2. Give it an appropriate name, like Video or something, and make sure it is selected under Playing Now in the tree.
3. Go to Tools > Options > Audio. You'll notice that this options panel is reset to the defaults. That's because each Zone has independent Audio, Video, and DSP settings.
4. Change Output Mode to WASAPI Event Style (probably).
5. Click Output Mode Settings and change the Device from (Default) to your HDMI output.
6. Leave everything else there alone, and click OK.
7. Still in the Options > Audio section, if you'd like, you can enable Bistreaming to pass-through TrueHD, DTS, Dolby Digital, and the rest to your receiver. I'd leave this off for now, but if you want it, you can turn it on here later (but you should consider not enabling it and using MC to decode, it does a better job than my Denon).
8. Switch to Options > Video. I'd try Red October Standard here, unless you know you have a very powerful machine (modern Core i5 or better, with a decent GPU). You can try HQ later. Just get it working now.
9. Close the Options panel and open the DSP.
10. Check the Output Format box, and set the Channels combo box to 5.1.
11. Change Bitdepth to the proper bit depth for your HDMI output (probably 24-bit unless you know better).
12. Close the DSP and try Video playback.
It should work and come out the proper audio output. Now you can switch manually back and forth between your two zones for stereo-via-the-DAC music playback and hdmi-via-the-receiver video playback. Once you get that far and it is working right, then you can set it up to automatically switch back and forth between your "Music" zone (your existing one), and your new Video zone.