Error "Failed to locate an output device" after deactivating one of two displays in windows

[Justify87]

Is there an existing issue for this?

• I have searched the existing issues

Is your issue described in the documentation?

• I have read the documentation

Is your issue present in the nightly release?

• This issue is present in the nightly release

Describe the Bug

I set sunshine to only use DISPLAY2 for capturing output. After deactivating Monitor 2 in windows, Sunshine terminates without being able to correct my setting in the webui.

Expected Behavior

Fall back to DISPLAY1 or at least give an error message in the web ui, instead of completely terminating the application.

Additional Context

I have a HDMI dingle to fake a monitor, So I can turn off the real one, while still being able to stream via sunshine. HDMI allows for that. Displayport does not. Sunshine will capture the output to my fake HDMI monitor and I can save some power, cause I dont have to leave the real monitor on. However I sometimes have to disable the fake monitor, because app-windows get trapped there from time to time.

Host Operating System

None

Operating System Version

Windows 11

Architecture

64 bit

Sunshine commit or version

18.3

Package

None

GPU Type

Nvidia

GPU Model

1660 Super

GPU Driver/Mesa Version

528.49

Capture Method (Linux Only)

No response

Relevant log output

[2023:02:15:18:15:08]: Info: Compiling shaders...
[2023:02:15:18:15:08]: Info: Compiled shaders
[2023:02:15:18:15:08]: Info: Trying encoder [nvenc]
[2023:02:15:18:15:08]: Info: ddprobe.exe [1] [\\.\DISPLAY2] returned: 0x00000000
[2023:02:15:18:15:08]: Info: Set GPU preference: 1
[2023:02:15:18:15:08]: Error: Failed to locate an output device
[2023:02:15:18:15:08]: Error: Failed to locate an output device
[2023:02:15:18:15:09]: Error: Failed to locate an output device
[2023:02:15:18:15:09]: Error: Failed to locate an output device
[2023:02:15:18:15:09]: Error: Failed to locate an output device
[2023:02:15:18:15:09]: Error: Failed to locate an output device
[2023:02:15:18:15:09]: Error: Failed to locate an output device
[2023:02:15:18:15:10]: Error: Failed to locate an output device
[2023:02:15:18:15:10]: Info: Encoder [nvenc] failed
[2023:02:15:18:15:10]: Error: Couldn't find any working encoder matching [nvenc]
[2023:02:15:18:15:10]: Info: // Testing for available encoders, this may generate errors. You can safely ignore those errors. //
[2023:02:15:18:15:10]: Info: Trying encoder [quicksync]
[2023:02:15:18:15:10]: Error: Failed to locate an output device
[2023:02:15:18:15:10]: Error: Failed to locate an output device
[2023:02:15:18:15:10]: Error: Failed to locate an output device
[2023:02:15:18:15:11]: Error: Failed to locate an output device
[2023:02:15:18:15:11]: Error: Failed to locate an output device
[2023:02:15:18:15:11]: Error: Failed to locate an output device
[2023:02:15:18:15:11]: Error: Failed to locate an output device
[2023:02:15:18:15:11]: Error: Failed to locate an output device
[2023:02:15:18:15:12]: Info: Encoder [quicksync] failed
[2023:02:15:18:15:12]: Info: Trying encoder [amdvce]
[2023:02:15:18:15:12]: Error: Failed to locate an output device
[2023:02:15:18:15:12]: Error: Failed to locate an output device
[2023:02:15:18:15:12]: Error: Failed to locate an output device
[2023:02:15:18:15:12]: Error: Failed to locate an output device
[2023:02:15:18:15:12]: Error: Failed to locate an output device
[2023:02:15:18:15:13]: Error: Failed to locate an output device
[2023:02:15:18:15:13]: Error: Failed to locate an output device
[2023:02:15:18:15:13]: Error: Failed to locate an output device

[Nonary]

This issue isn't really highlighting the problem, but rather makes it seem like you're upset that disabling a monitor makes the stream end. That's not really an issue, that would be like being upset that the display stopped working when you unplugged it.

I tested the issue myself and confirmed that if the display isn't found, sunshine does not function at all and it's impossible to fix it with the web UI alone. In other words, it breaks Sunshine to the point where it cannot even launch the web UI.

Thanks for the report.

As for suggestions, you can use my script to automate swapping displays without you having to worry about manually disabling them.

https://github.com/Nonary/MonitorSwapAutomation/releases/tag/production

[Justify87]

I'm not upset, but thanks for the tool

[Nonary]

This was indirectly fixed with #1094

[Dracalis]

I encountered this error from doing a similar thing. In the Configuration > Audio/Video > Output Name field, I typed a display number that didn't exist. This caused Sunshine to get the same error as you and close on startup, locking me out of further changes.

How to Fix It

In your root Sunshine folder, open sunshine.conf with Notepad or an IDE. Find the line with output_name = and set it to the correct monitor. For example:

output_name = \\.\DISPLAY1

In Windows, you can be certain of your monitor number going into System Settings > Display > Display, then hitting the Identify button — though it's easy to guess. Bear in mind that the count starts at 1, not 0, which is where I made my initial error.