I've been using Plex for playback on the Roku 3 for quite some time, and haven't had any issues. This just started happening yesterday. I can work around it, but thought I'd post in case anyone else is having similar issues or knows the cause.
I have a Roku 3 on the same gigabit wired network as my Plex Server. The Roku is connected via HDMI to a Sony AV Receiver which is connected via HDMI to a Samsung TV. Playing back a 1080P MKV with DTS audio, about 20 minutes into the file, the audio mutes. If I press any button on my Roku remote, the Roku reboots itself. I can restart playback, and when it gets to the same spot, the same thing happens. If I resume playing from that spot, it happens a few minutes further in to the video file. I verified that it is using direct play.
I've had this happen with two files so far, they are both 1080P and DTS, but it's a very small sample size. I have plenty of other 1080P DTS files that play with no issues.
Since the whole Roku crashes and restarts, not just the Plex app, maybe it's just something weird with my Roku, like it's overheating or something.
It's a minor inconvenience at worst -- just thought I'd post to see if anyone had any ideas on it. Thanks!