Hi Bob,
I just tried removing my Hifiberry Digi+ Pro and USB dac which switched the output to pulsealsa. Tried the OK button - still crashes! I assume you burned a clean install of Full Raspian, not Lite, and still got no error. I'm stumped!
I did notice on both my "Previous Log" and mwillems "Previous Log" the last line is "Playback: CConfigureALSADlg::OnOK: Start". I am wondering if you call anything outside Mediacenter, such as ALSA and if my version and the Arch version of ALSA has been changed in some way causing a hard processor crash. That wouldn't leave any error condition for JRiver to process.
Update: I did a run from the terminal trying to get a coredump, no luck for me, but did get this response from the system:
"ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Connection refused Segmentation Fault"
JRiver Log included.
Thanks Duncan.