Is the affected network Zone connected with Ethernet or WiFi?
· Ethernet
Does the issue affect all file formats?
· The issue affects *multiple/all* file formats.
Does the issue happen with local library music, streaming service music, or both?
· *Both streaming and local* *library* music are affected.
Do you encounter any playback errors with the "System Output" Zone?
· The System Output has the same problem as my other Zone.
Do you have a complex network setup?
· I don't have a mesh network, but I use *managed network switches*
Your local network might need some re-arranging to support Roon.
· None of the suggestions have helped me. I'd like to submit a support request.
Do you have an approximate timestamp of when the issue last occurred?
· Sunday Jan 18 between 9am-11:10am PST - Multiple crashes
What are the make and model of the affected audio device(s) and the connection type?
· Lyngdorf MP-40
Describe the issue
Lyngdorf MP40 “will not initiate” Roon session or suddenly disappears as available Roon Endpoint
Describe your network setup
I have had Roon since it was Sooloos. My network is configured properly with NAS storage and MAC Mini based roon server. This seems to have started when Mac moved to OS 15 and beyond. Tahoe especially.
Starting with macOS 15 (Sequoia) and later, including Tahoe, Apple introduced tighter and less transparent local network security controls. In some cases, this can cause Roon to intermittently lose access to the local network, which may result in networked endpoints (such as the Lyngdorf MP-40) disappearing or failing to initiate playback sessions.
Please check the following on your Mac mini:
Go to macOS System Settings → Privacy & Security → Local Network
Make sure Roon and Roon Server are both allowed
If they are already enabled, toggle them off and back on
Reboot the Mac
Test again and see if the behavior persists
We’ve seen this resolve similar endpoint discovery and dropout issues on macOS 15+ systems.
Thank you. I have taken these steps. I have rebuilt both the RAAT server folder and the RoonServer folders multiple times. I have also turned off and on the permissions for Local Network Access on more than 15 occasions:)
We see from a fresh Roon Server diagnostic that Roon is losing the Lyngdorf MP-40, which is not completing the RAAT “prepare/setup” handshake:
[zoneplayer/raat] Failed to prepare Lyngdorf MP-40 in 15000ms. Giving up
[zoneplayer/raat] failed to setup any endpoints..giving up
This is telling us that Roon successfully:
Opens the file
Starts buffering
Negotiates format
Sends setup to the MP-40
But the MP-40 does not fully acknowledge or stabilize the RAAT stream fast enough. Roon then kills the stream, resulting in:
Track Stopped Due to Error
We do see something interesting - the first tracks’ format was 44.1 kHz / 16-bit, while the second was 96 kHz / 24-bit.
Each time Roon sends:
[raatclient] SENT {"request":"setup","format":{...}}
Shortly afterward, the MP-40 fails to fully prepare. This pattern strongly suggests the MP-40 is choking during stream re-initialization, especially on format changes.
If possible, could you check the firmware on the MP40? See if there are any updates, and if not, see if you’re able to reinstall the current version.
After that, lets test out locking the sample rate temporarily.
In Roon:
Device Setup → Lyngdorf MP-40
Disable DSP
Set Max Sample Rate = 44.1 kHz
Disable sample rate conversion
If stability returns, it could be a format-change bug.
Yes. I have reinstalled, rebuilt the Raat Server folder and the Roon Server folders on multiple occasions. I have tried every suggested step I have been able to locate. I can confirm that it is only the lyngdorf that behaves this way. The other (2) zones play without issue and without interruption.
Can you please provide more details regarding your network setup? How is the Lyngodorf and Roon Server connected? Are they on the same switch? What is the model/manufacturer of the networking gear? Are you able to reboot your network and does that help, even temporarily?
The network is not the issue as nothing on this network has changed for years of solid performance from Roon. I am happy to discuss more details directly, but not on a public forum.
To better understand what’s happening on the Lyngdorf side, could you please help us clarify how the issue presents itself directly on the MP-40 when playback drops or the device disappears in Roon?
Specifically, when the issue occurs:
What do you see on the MP-40 itself?
Does the front panel/UI freeze, reboot, or show any error message?
Or does it appear responsive and normal?
Does the MP-40 temporarily lose network connectivity?
For example, does it disappear from the Lyngdorf control app or web interface at the same time?
Or is it still reachable while Roon loses it?
Does audio stop immediately, or does it fail only when starting a new track / changing tracks?
Does the MP-40 recover on its own, or does it require:
a manual input change,
a reboot,
or a power cycle to reappear in Roon?
If possible, do you notice whether this happens more often when switching sample rates or formats (e.g. 44.1 → 96 kHz)?
This will help us determine whether the endpoint is restarting, temporarily dropping off the network, or remaining stable while the RAAT session fails.
Thank you — the more detail you can share here, the easier it will be to narrow this down.
While it will require you to do a little more testing, we’ll need the information @vadim has outlined above in order to proceed. Please let us know if we can clarify any of the five tests he’s described.
Please also, if you’re willing, share at least the basics of how you’ve connected these two devices across your local network. Do you have a mesh network, for instance?
Without any sense of the network topology, we’re unable to confirm how multicast traffic that carries device discovery announcements will be routed between your server and this endpoint.
We’ll watch for your reply and proceed from there.
Hi All - I was able to test several things this week and I believe I was able to isolate the snag & resolve the issue. I will be testing through the weekend to be sure I am correct. Will reply back Monday.
We wanted to reach out to confirm you weren’t experiencing any further issues. This thread will shortly auto-close without any new activity from the OP. We’ll of course keep it open if you require additional troubleshooting.
Hi There - I have 100% ruled out multicast issues, Roon software and MAC OS issues. This took a little time as I needed to go one variable at a time. Of course, the last test was rolling the MP40 back to 5.3.0 and, of course, this stopped the constant port flapping from that device. I have had Roon playing for over 24 hours without the pre-amp dropping out of Roon and/or the stream stopping. I believe this is now resolved. Thanks for the patience and the help.
