Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
I have a 2017 Roku Ultra. I put an mkv encoded with h.265 in its own folder on my DLNA server. When I browse to it in the media player, it says "no compatible media found in: <foldername>". However, I can play the video via the DLNA server on my phone with VLC, so minidlna is serving it correctly. I can also play h.264 encoded mkvs, and they appear in the Roku browser correctly.
I copied the same h265 mkv to an ext3 formatted flash drive, and then Roku Media Player can see it and will play it. So the file is compatible.
There seems to be some bug preventing my Roku Ultra from seeing (and playing) compatible h.265 mkv files via DLNA.
It's more likely that your DLNA server isn't listing the file accurately. I have the same occasional problem with my Serviio, but can see others. The profile has to accurately identify the player and provide correct information back to the player. What DLNA server are you using?
Sorry, saw you're using MiniDLNA. I don't know what sort of profiles it offers, but most likely it doesn't recognize any Roku as capable of playing H265.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.