Cannot pair device (Error 4: Request Timed out)

[Duckrinium]

READ ME FIRST!
If you're here because something basic is not working (like gamepad input, video, or similar), it's probably something specific to your setup, so make sure you've gone through the Troubleshooting Guide first: https://github.com/moonlight-stream/moonlight-docs/wiki/Troubleshooting

If you still have trouble with basic functionality after following the guide, join our Discord server where there are many other volunteers who can help (or direct you back here if it looks like a Moonlight bug after all). https://moonlight-stream.org/discord

Describe the bug
A clear and concise description of what the bug is.
Windows client fail to pair to Linux sunshine, raising "Request timed out (Error 4)", Sunshine is radio silent but responds to pin just fine (it clearly sees the pin request!)

Steps to reproduce
Any special steps that are required for the bug to appear.

• Connect to ZeroTier
• Start Sunshine on host
• Open Moonlight
• Start pairing the device
• Enter PIN provided in Sunshine's webui
• Web ui says "Success! Please check Moonlight to continue" and a few seconds later, Moonlight will show an error.

Screenshots
If applicable, add screenshots to help explain your problem. If the issue is related to video glitching or poor quality, please include screenshots.

Affected games
List the games you've tried that exhibit the issue. To see if the issue is game-specific, try streaming Steam Big Picture with Moonlight and see if the issue persists there.

Other Moonlight clients

• Does the issue occur when using Moonlight on iOS or Android?

Android under the same wifi network + zerotier network performs fine and pairs successfully and is able to stream.

Moonlight settings (please complete the following information)

• Have any settings been adjusted from defaults?
• If so, which settings have been changed?
• Does the problem still occur after reverting settings back to default?

Nothing was changed, basically a cold start, I even have reset Moonlight a few times.

Gamepad-related issues (please complete if problem is gamepad-related)

• Do you have any gamepads connected to your host PC directly?
• Does the problem still remain if you stream the desktop and use https://html5gamepad.com to test your gamepad?
  • Instructions for streaming the desktop can be found here: https://github.com/moonlight-stream/moonlight-docs/wiki/Setup-Guide

Client PC details (please complete the following information)

• OS: [e.g. Windows 10 1809]
• Moonlight Version: [e.g. v0.9.0]
• GPU: [e.g. Intel HD Graphics 520]
• Linux package type (if applicable): [e.g. Flatpak]

Windows 10 22H2
Moonlight 6.0.1 (seems to be every version is affected, have tried 4.X and 6.0.0)
Intel UHD Graphics

Server PC details (please complete the following information)

• OS: [e.g. Windows 10 1809]
• Sunshine or GeForce Experience version: [e.g. Sunshine v0.21.0]
• GPU: [e.g. AMD Radeon RX 7900 XT]
• GPU driver: [e.g. 24.1.1]

Arch Linux
Sunshine 0.23.1
i5-10400F
GTX 1660 | v. 360

Moonlight Logs (please attach)

• On Windows, Moonlight-###.log files can be found in %TEMP%. Simply type that into the File Explorer path field to navigate there.
• On macOS, Moonlight-###.log files can be found in /tmp. In Finder, press Cmd+Shift+G, then type /tmp to navigate there.
• On Linux with the Flatpak, logs print to the terminal when running with the command: flatpak run com.moonlight_stream.Moonlight
• On Linux with the Snap, logs print to the terminal when running with the command: moonlight

Additional context
Anything else you think may be relevant to the issue
Android does what PC doesn't, which is weird, same Wi-fi network, same zerotier network. Ports have been checked on server side and Moonlight can do any port. I don't know what else I can tackle here. It worked before. Now it fails at the very end. In screenshots you can even see that I use SSH to enter pin codes in Sunshine so I definitely don't have problems with connecting to my PC and Sunshine acknowledge the pair by displaying "Please insert pin" whenever I request the pair. I have reset Sunshine as well.

[Duckrinium]

Update! I've launched moonlight (flatpak) and zerotier on EndeavourOS (arch) on the same computer (via LiveUSB) and surprisingly that worked!
So something with my Windows PC it seems, strange even though I gave every permission to moonlight in Firewall

[Duckrinium]

It seems that the issue was caused by ZeroTier as it was super slow, so slow that it made those timed out. Apologies

[CPioGH2002]

Since that's the exact error I was receiving when trying to pair a Windows client (Moonlight) to a Linux server (Sunshine), I hope you don't mind me stating some more things to check for people running into similar problems.

While you concluded that "ZeroTier was super slow", which seems a bit vague (while not doubting your judgement), I wanted to add some details concerning my case which, eventually, got solved. Thanks to your initial note, I shall add.

Problem description:

First of all, the problem only arose between the described "mixed" setup of a Linux server (running Sunshine, streaming on the ZeroTier interface) and a Windows machine (Moonlight, connected to the server via ZeroTier) and resulted in the exact same errors you are describing.

Strangely enough, no problems could be reproduced while using other Linux machines to connect or even Linux machines with Windows VMs. All of those worked when trying to pair and, later, stream. Just the Linux Server to (native) Windows client never got over the pairing process with the dreaded "timed out" (Error 4) message.

The ZeroTier setup between these two machines was sound and functional on all other occasions, allowing other streaming solutions to work, RDP, SSH, data transfers, you name it. Nothing regarding the connection's latency or speed showed any problem, only the Moonlight to Sunshine pairing process did.

Solution:

In the end, it was solved by enabling the Linux Sunshine server to make use of IPv6. Usually, this is the default but I happened to disable IPv6 since the server also ran on a VPN for other purposes and I wanted to minimise the risk of IP leaks. As said, this setup didn't prevent any other machine from connecting to the Sunshine server, be it locally or via ZeroTier (=remotely).

But the enabled IPv6 seemed to have allowed the Windows client and Linux server to connect... differently which, later on, rendered the pairing process operable, as opposed to before. So it wasn't about the actual speed or latency of the ZeroTier connection but about how it was established.

So if anyone runs into this well-done thread (you gave plenty of details, vital ones) and is looking for some pointers, the note on the ZeroTier connection method being a possible source of errors surely is worth investigating. :-)

[Duckrinium]

While you concluded that "ZeroTier was super slow", which seems a bit vague (while not doubting your judgement)

Ah! Sorry, something was wrong with doing that through ZeroTier, as when it was successful, stream was rather low quality and laggy. I've switched to NetBird and that did work, so yeah.

[CPioGH2002]

I see. With those symptoms, your statement does make sense. Then my issue (which is solved now, as described above) differed in that ZeroTier had a normal and very useful throughput, rendering the pairing issues even more puzzling.

Anyway, if one ever runs into the same problem, he/she will find your thread (as I did) and hopefully get some ideas on how to fix them. :-)