I run a FreeNas box and have its Plex server SW installed. Had this for many years now. I just upgraded to Win 10 on my HTPC and installed the Plex HT from the Windows Store. Movies run for a couple of minutes then they drop off to the starting screen with no error message.
Is the Plex HT sw purchase only? I was going to purchase but I cannot do so until I see it working as it should.
Pled Home Theater isn’t on the Windows Store. It’s also be abandoned and is not developed. OpenPHT is the most similar to it. The app on the windows store is the Plefor Windows app, not the same thing.
If you don’t have a plexpass and don’t purchase the app it is limited to a minute of playback.
But that limitation doesn’t include the above mentioned OpenPHT - so there’s no need to buy anything to watch Plex.
Off the top of my head, on a PC;
Plex Web - free but limited in codec support etc (should be avoided in a HTPC setup)
PHT - free but discontinued and probably does not work very well with the latest PMS (I’ve seen reports about this so I would avoid it)
OpenPHT - community-driven fork of PHT, works very well (especially on that little Odroid box!)
Plex UWP client (from the store) - not free but mostly aimed for tablets/phone (usage scenario on a laptop often includes the sync option that still exists there)
Yeah my comment was only addressed at the UWP app, there are plenty of choices 
For a HTPC box, OpenPHT is probably the best choice.
I know, Wilhelm, that you know that I just clarified for the OP, that’s all. No harm meant.
