I use Plex on my computer, phone, and Xbox One. It was working great on all three before. Now, the Xbox One app is very slow, the other apps are fine. It is a very weird place to be slow too. So I can browse around my collection of 1000 movies and it is quite fast. The problem is when I click on a movie. It loads everything but the thumbnail quickly. While it is loading the thumbnail, there is also no “cursor” meaning I can’t click play or anything else. It takes ~20 seconds to load the thumbnail. If I back out to the movie listing and click the movie again, it does the same thing. It does it for every movie. Everything else is very fast, no buffering or slow speed navigating anywhere else. I can do multiple transcoding streams without any stuttering, it is all perfect other than the slow thumbnails. I have restarted both the Xbox One and server many times. The server is an Intel NUC running Ubuntu with Intel Core i5-6260U, 16GBB DDR4 ram, M.2 SSD. Everything is running on gigabit ethernet. The server has plenty of power. Any suggestions on how to fix it? The thumbnails being slow wouldn’t be a big deal but it makes the app completely unresponsive while they are loading. Thanks! 
I am having the same exact issue. Ever since the newest update to the Xbox One Plex app it has been excruciatingly slow, unresponsive and takes forever to do anything. it works fine on any other client/platform I use it on.
I have uninstalled and reinstalled the app, done a hard reset on my Xbox One and am still encountering the same issue.
its the latest version of the app, it’s completely 100% borked - don’t know whats taking them so long to just downgrade it.
It is much worst now but I was having the issue before the latest version came out only with certain series. Simpsons was one, so I have to assume it’s related to volume. The larger the series the longer the delay.
The slowness and delay in playing is INSANE now.
The worst (most noticable) part is when you go to Movie/TV show/etc… and then WAIT for the page to load so that you can press play.
I have been considering going out and buying a couple more AppleTV’s to use in the livingroom (use it in the bedroom now for Plex) instead of my Xbox One’s because it is so painful now. Hoping they update this mess. 
I think it’s a combination of two factors. The new Xbox One client and the new server version 9.17.2. I rolled back to server version 0.9.16.6 and the loading into a movie is a lot better, but still not as fast/smooth as the older client. But I’m also in the Xbox preview program, so that could be a reason for the client still being slower than usual after downgrading my server.
It’s just as slow with 9.16.6 for me. I upgraded to 9.17.2 to see if it helped. No.
What’s weird is we have had no input from any devs about it. Or at least acknowledging that there is an issue or a fix on the way.
I think there was one comment that they couldn’t reproduce it. I think it’s a library size issue, IMO.
I was runnign Plex on Xbox 360 and it worked fine. Upgraded to Xbox One and it locks up for a long time when you select a video and it goes to the screen for just the video or when it finished and returns to the vid screen. They all seem to play. But the lockup for a min or so is really annoying.
I believe I’ve identified the cause of the slowness for some users, and am working on a fix. The intention is to submit an update with this fix, and some others, as soon as possible.
@moussa said:
I believe I’ve identified the cause of the slowness for some users, and am working on a fix. The intention is to submit an update with this fix, and some others, as soon as possible.
Good work!
I just wanted to say that I am also having this issue with the most recent version (1.6.1.0). The previous version was very fast, so this is now very noticeable. I have a large library, but the size of the library didn’t change between Plex app updates. Very nice to hear that there is a fix incoming! Thank you!
thanks @moussa because it’s just unusable in this version for xbox one. I’m sorry to say this, but i just returned to my raspberry pi 2 with rasplex. It’s a shame because I love the xbox one app, it was much more responsive and usable.
I am eager to see the result
Also having this issue. Have a fairly large library, but only the version of Xbox1 player changed. I have noticed anything amiss in other platforms (Roku, Smansung, Web). So hopefully the fixes that Moussa has working will solve the problem.
Same problem here. It’s excruciating.
+1 - Slowness is really bad on our Xbox One here… Latest Xbox Updates installed, just updated the Plex Server, running 1.0.0.2261
FWIW. I’ve been able to somewhat workaround the issue (assuming its the same issue) – selecting a movie from the Movies Library takes forever. By starting to watch it on another computer (just seek ahead) it will show up “Continue Watching”. When I select that from the Plex Home screen for the Xbox One I don’t have any issues with it loading or starting to play.
Any sign of a fix/ETA yet for the slowness on 1.6.1.0?
June 27 … still not much usable. Can’t back to the previous screen and everything locked up.
