Contributor I

Answered

Error with Plex: "Unable to play [track] - the connection to Plex was lost"

17 replies
2432 views

Hello. I am currently unable to play any track in my Plex music library through my Sonos S1 system. I can see and browse music fine, but all playback attempts fail with the message shown the title. Further, I am unable to cast to any Sonos device from the Plex app on Android or Windows.

For an additional description of my issue, see this thread on the Plex forums:

Error Streaming to SONOS - Plex Players / Streaming Devices - Plex Forum

Based on errors generated in the Plex logs, this appears to be a TLS handshake issue with the Plex service. My issue is similar or identical to what several users have reported here on this earlier thread:

Plex integration: "Unable to play '[track]' - the connection to Plex was lost" | Sonos Community

However, I have been unable to resolve it.

My Plex server is fully accessible outside my network. My router (eero) claims to support NAT hairpin, and I can see my Plex server from inside my network using my external ISP-assigned public IP address. I have deleted and recreated the Plex service in Sonos and restarted the Plex server to no avail.

My configuration is as follows:

Plex host: Headless install of Windows 11 Pro 22621.2134 on AMD Ryzen 9 6900HX
Plex Server Version#: 1.32.5.7349
Player Version#: SONOS S1 system (11.10.1, latest), all Plex client apps I have tried
Router: Eero Pro 6E mesh running software revision 6.15.3 (current)
LAN: mix of hardwired and wireless (most Sonos devices are hardwired)

I would welcome any thoughts or suggestions.

This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

Corry PAnswer

Sonos Staff

Hi @User246959

Thanks for reporting this. I was able to verify this on my own system, but also had trouble connecting to my Plex server via web on my phone to change the setting back - HTTP didn’t work (expected), but Chrome kept reporting that the SSL (Secure Socket Layer) implied with HTTPS was not working properly and that the connection was not secure, though I could connect using HTTPS in the URL.

I’m not sure if it is related, but I also seem to have a problem getting my server’s Remote Access page to say that remote access is working, even though it is.

I’ve flagged this with the team and we’ll look into it, but I recommend also getting in touch with Plex’s support team.

If you don’t need remote access to your Plex server, one option would be to disable the Remote Access feature in the server settings - then it matters far less if security is used or not, as only devices on your network will be able to connect anyway.

I hope this helps.

"Common sense is the collection of prejudices acquired by age eighteen." - Albert Einstein

Ken_Griffiths

Do you have UPnP auto-port forwarding enabled on the router? If not, then try enabling that aswell as forwarding port 32400 to your Plex server and see if that resolves your issue. I’ve read (somewhere) that some routers need to have UPnP enabled for things to work. That said my Plex server/Sonos service work fine without it, but it still maybe worth a shot.

U

User246959Author

Contributor I

Do you have UPnP auto-port forwarding enabled on the router?

Thank you for the suggestion. Originally, I had manually forwarded the needed port for Plex. I changed this to use UPnP instead, but it made no difference. Playback on Sonos continues to fail with the same TLS error being displayed by Plex:

CERT: incomplete TLS handshake from [::ffff:xxx.xxx.x.xx]:35841: no shared cipher (SSL routines)

It appears to be some kind of certificate error, but I would have no idea how to resolve it, or whether the problem is on the Sonos or Plex end.

Since the service is apparently working for others, it could also be something with my LAN or router, but from what I can tell, my environment meets all the necessary requirements.

Ken_Griffiths

Did you try manually forwarding the port aswell as enabling UPnP, rather than instead of?

Ken_Griffiths

I also came across this link when searching for the error … maybe something in the thread will assist you:

https://github.com/RasPlex/RasPlex/issues/645

U

User246959Author

Contributor I

Did you try manually forwarding the port aswell as enabling UPnP, rather than instead of?

I'm not sure this is possible for Plex.

In the Plex Media Server admin UI, these two things seem to be mutually exclusive. After disabling custom port forwarding on my router for Plex, I had to disable the manual port forward setting in the Plex Media Server in order for it to create a connection via UPnP. Reactivating the manual port setting seems to clear any existing UPnP connections.

UPnP has always been enabled on my network, even when I was using manual port forwarding, for what it's worth.

U

User246959Author

Contributor I

I also came across this link when searching for the error … maybe something in the thread will assist you:

https://github.com/RasPlex/RasPlex/issues/645

Thank you.

From reading through this, it seems the most salient suggestion was to disable authentication for local clients. I do not believe this can be applied to Sonos, since Sonos always streams from a Plex server remotely, and not from a direct LAN connection, if I understand its design correctly.

Ken_Griffiths

I’m also running the same Plex server version 1.32.5.7349, albeit on my Netgear NAS box, but presently use it with the S2 App… give me a moment and I will check the server with the latest S1 Sonos App and report back.

Ken_Griffiths

I added the Plex service to the S1 App v11.10.1 and Plex-audio playback is all working okay here (see attached) - so I guess it’s likely going to be something local to your setup, perhaps?

Have you ever had Plex working with your current router/network setup, or is this a new setup? If it’s new, maybe it’s a setting on your Eero router that’s blocking access🤔? Any firewall etc?

U

User246959Author

Contributor I

@Ken_Griffiths: thank you so much for doing this testing. It is encouraging to hear that it all works as designed in your setup.

I agree it is likely something local to my configuration, but I have investigated all the usual suspects. Eero sadly does not expose many advanced settings to tweak, though I can have another look.

The only interesting thing about my current setup is that I transferred Plex to new hardware recently, using the standard process described here: Move an Install to Another System | Plex Support. But I have done this multiple times, and nothing untoward happened with this migration.

One thing I have not tried yet is to log out of my Plex server altogether, and then “reclaim” it. I will give this a shot and see if it helps, and then report back when I am able.

U

User246959Author

Contributor I

Well, I got this sorted.

The problem was that the Plex advanced network setting for secure connections was set to “required” instead of “preferred”. After making this change, I can now stream from Plex again.

This was unexpected, because Plex explicitly lists Sonos as supporting secure connections here:

How to Use Secure Server Connections | Plex Support

This leads me to believe that there may still be an issue on the Sonos side that would be worth looking into, since the behavior does not match what Plex describes. I don’t know if the Sonos developers monitor these discussions, but I’d be willing to offer more information to them if needed.

For security’s sake, I would prefer to run my Plex server requiring secure connections for all apps, so I hope that this could be addressed by Sonos in the future.

@Ken_Griffiths : thank you for your efforts to help with this.

Show more replies

Sign up

Login to the community