I know MPEG-DASH support is in Beta and it's great to see the support for it coming. The current implementation has a bug on the SegmentList - here's a snippet:
<SegmentList timescale="0" duration="0" startNumber="1">
Duration and Timescale are both 0. This is based on an MPEG-4 which is audio-only so perhaps the lack of a video track is causing this issue?
Again, I know this is in Beta, just wanted to pass it along.