Cannot open web UI url through Firefox (MSIX/Microsoft store version)

Start by locating the Windows code that opens Sunshine’s web UI in the default browser; the issue does not name a file or test. Reproduce with Firefox’s Microsoft Store version as the default browser and compare with the official Firefox version and Vivaldi. Done means the web UI opens in the Store version while the other reported browsers continue to work.

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 latest beta/pre-release?

This issue is present in the latest pre-release

Describe the Bug

Sunshine cannot open web UI url when default browser is Firefox (MSIX/Microsoft store version).

Expected Behavior

Open UI through Firefox.

Additional Context

Can open UI that default browser is another.
I tested Vivaldi and Firefox (official version) are correct.

Host Operating System

Windows

Operating System Version

Windows 10 22H2 19045.7725

Architecture

amd64/x86_64

Package

Windows - msi installer (recommended)

GPU Type

AMD

GPU Model

Radeon RX 6700 XT

GPU Driver/Mesa Version

26.10.1

Capture Method

No response

Apps

Log output

[2026-11-04 15:57:19.221]: Info: Sunshine version: 2026.1103.235308 commit: 2efa60fb85a54fb61495d12c6b22d405e89627d3
[2026-11-04 15:57:19.221]: Info: Package Publisher: LizardByte
[2026-11-04 15:57:19.221]: Info: Publisher Website: https://app.lizardbyte.dev
[2026-11-04 15:57:19.221]: Info: Get support: https://app.lizardbyte.dev/support
[2026-11-04 15:57:19.221]: Info: config: 'controller' = disabled
[2026-11-04 15:57:19.221]: Info: config: 'gamepad_driver' = all
[2026-11-04 15:57:19.221]: Info: config: 'locale' = zh
[2026-11-04 15:57:19.222]: Info: Provided workaround settings for SettingsManager:
{
  "hdr_blank_delay": null
}
[2026-11-04 15:57:19.232]: Info: Currently available display devices:
[
  {
    "device_id": "{889470b6-aa23-5acb-8471-009816631fba}",
    "display_name": "\\\\.\\DISPLAY5",
    "edid": {
      "manufacturer_id": "GSM",
      "product_code": "5C6D",
      "serial_number": 64904
    },
    "friendly_name": "LG ULTRAGEAR",
    "info": {
      "hdr_state": "Disabled",
      "origin_point": {
        "x": 0,
        "y": 0
      },
      "primary": true,
      "refresh_rate": {
        "type": "rational",
        "value": {
          "denominator": 1,
          "numerator": 144
        }
      },
      "resolution": {
        "height": 2160,
        "width": 3840
      },
      "resolution_scale": {
        "type": "rational",
        "value": {
          "denominator": 100,
          "numerator": 150
        }
      }
    },
    "is_internal": false
  },
  {
    "device_id": "{e262bdb8-d525-561e-a8ef-4ee621c5caa3}",
    "display_name": "\\\\.\\DISPLAY34",
    "edid": {
      "manufacturer_id": "LGD",
      "product_code": "05C0",
      "serial_number": 0
    },
    "friendly_name": "",
    "info": {
      "hdr_state": null,
      "origin_point": {
        "x": -1920,
        "y": 1080
      },
      "primary": false,
      "refresh_rate": {
        "type": "rational",
        "value": {
          "denominator": 1,
          "numerator": 120
        }
      },
      "resolution": {
        "height": 1080,
        "width": 1920
      },
      "resolution_scale": {
        "type": "rational",
        "value": {
          "denominator": 100,
          "numerator": 100
        }
      }
    },
    "is_internal": false
  }
]
[2026-11-04 15:57:19.617]: Info: nvprefs: No need to modify application profile settings
[2026-11-04 15:57:19.618]: Info: nvprefs: Changed OGL_CPL_PREFER_DXPRESENT to OGL_CPL_PREFER_DXPRESENT_PREFER_ENABLED for base profile
[2026-11-04 15:57:19.757]: Info: Compiling shaders...
[2026-11-04 15:57:19.879]: Info: Compiled shaders
[2026-11-04 15:57:19.887]: Info: [libvirtualhid] initialized windows-umdf backend
[2026-11-04 15:57:19.887]: Info: [libvirtualhid] created mouse 2
[2026-11-04 15:57:19.894]: Info: // Testing for available encoders, this may generate errors. You can safely ignore those errors. //
[2026-11-04 15:57:19.894]: Info: Trying encoder [nvenc]
[2026-11-04 15:57:20.067]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:20.068]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:20.068]: Info: Using realtime GPU priority
[2026-11-04 15:57:20.068]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:20.068]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:20.069]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:20.069]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:20.069]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:20.071]: Info: Encoder [nvenc] is not supported on this GPU
[2026-11-04 15:57:20.092]: Info: Trying encoder [quicksync]
[2026-11-04 15:57:20.216]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:20.216]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:20.216]: Info: Using realtime GPU priority
[2026-11-04 15:57:20.216]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:20.217]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:20.217]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:20.217]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:20.218]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:20.220]: Info: Encoder [quicksync] is not supported on this GPU
[2026-11-04 15:57:20.239]: Info: Trying encoder [amdvce]
[2026-11-04 15:57:20.360]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:20.360]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:20.360]: Info: Using realtime GPU priority
[2026-11-04 15:57:20.361]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:20.362]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:20.362]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:20.362]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:20.362]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:20.366]: Info: Creating encoder [h264_amf]
[2026-11-04 15:57:20.366]: Info: Color coding: SDR (Rec. 601)
[2026-11-04 15:57:20.366]: Info: Color depth: 8-bit
[2026-11-04 15:57:20.366]: Info: Color range: JPEG
[2026-11-04 15:57:20.414]: Info: Streaming bitrate is 1000000
[2026-11-04 15:57:20.422]: Info: [D3D11VA @ 0000022ca312e980] AMF via D3D11.
[2026-11-04 15:57:20.477]: Info: Creating encoder [hevc_amf]
[2026-11-04 15:57:20.477]: Info: Color coding: SDR (Rec. 601)
[2026-11-04 15:57:20.477]: Info: Color depth: 8-bit
[2026-11-04 15:57:20.477]: Info: Color range: JPEG
[2026-11-04 15:57:20.525]: Info: Streaming bitrate is 1000000
[2026-11-04 15:57:20.534]: Info: [D3D11VA @ 0000022ca30a6fc0] AMF via D3D11.
[2026-11-04 15:57:20.592]: Info: Creating encoder [av1_amf]
[2026-11-04 15:57:20.592]: Info: Color coding: SDR (Rec. 601)
[2026-11-04 15:57:20.592]: Info: Color depth: 8-bit
[2026-11-04 15:57:20.592]: Info: Color range: JPEG
[2026-11-04 15:57:20.639]: Info: Streaming bitrate is 1000000
[2026-11-04 15:57:20.649]: Info: [D3D11VA @ 0000022ca2445f40] AMF via D3D11.
[2026-11-04 15:57:20.651]: Error: [av1_amf @ 0000022ca313db80] CreateComponent(AMFVideoEncoderHW_AV1) failed with error 30
[2026-11-04 15:57:20.651]: Error: Could not open codec [av1_amf]: Encoder not found
[2026-11-04 15:57:20.804]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:20.805]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:20.805]: Info: Using realtime GPU priority
[2026-11-04 15:57:20.805]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:20.806]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:20.806]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:20.806]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:20.806]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:20.941]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:20.941]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:20.941]: Info: Using realtime GPU priority
[2026-11-04 15:57:20.941]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:20.942]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:20.942]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:20.942]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:20.942]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:21.086]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:21.086]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:21.086]: Info: Using realtime GPU priority
[2026-11-04 15:57:21.086]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:21.087]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:21.087]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:21.087]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:21.087]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:21.093]: Info: Creating encoder [hevc_amf]
[2026-11-04 15:57:21.093]: Info: Color coding: SDR (Rec. 709)
[2026-11-04 15:57:21.093]: Info: Color depth: 10-bit
[2026-11-04 15:57:21.093]: Info: Color range: JPEG
[2026-11-04 15:57:21.149]: Info: Streaming bitrate is 1000000
[2026-11-04 15:57:21.158]: Info: [D3D11VA @ 0000022ca40507c0] AMF via D3D11.
[2026-11-04 15:57:21.364]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:21.365]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:21.365]: Info: Using realtime GPU priority
[2026-11-04 15:57:21.365]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:21.366]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:21.366]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:21.366]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:21.366]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:21.506]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:21.506]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:21.506]: Info: Using realtime GPU priority
[2026-11-04 15:57:21.506]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:21.508]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:21.508]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:21.508]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:21.508]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:21.662]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:21.663]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:21.663]: Info: Using realtime GPU priority
[2026-11-04 15:57:21.663]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:21.664]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:21.664]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:21.664]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:21.664]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:21.807]: Info: 
Device Description : AMD Radeon RX 6700 XT
Device Vendor ID   : 0x00001002
Device Device ID   : 0x000073DF
Device Video Mem   : 12243 MiB
Device Sys Mem     : 0 MiB
Share Sys Mem      : 16316 MiB
Feature Level      : 0x0000B100
Capture size       : 3840x2160
Offset             : 1920x0
Virtual Desktop    : 5760x2160
[2026-11-04 15:57:21.807]: Info: Active GPU has HAGS disabled
[2026-11-04 15:57:21.807]: Info: Using realtime GPU priority
[2026-11-04 15:57:21.807]: Info: 
Colorspace         : DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Bits Per Color     : 10
Red Primary        : [0.675781,0.311523]
Green Primary      : [0.268555,0.680664]
Blue Primary       : [0.149414,0.0556641]
White Point        : [0.313477,0.329102]
Min Luminance      : 0.101 nits
Max Luminance      : 603 nits
Max Full Luminance : 400 nits
[2026-11-04 15:57:21.808]: Info: Desktop resolution [3840x2160]
[2026-11-04 15:57:21.808]: Info: Desktop format [DXGI_FORMAT_B8G8R8A8_UNORM]
[2026-11-04 15:57:21.808]: Info: Display refresh rate [144Hz]
[2026-11-04 15:57:21.808]: Info: Requested frame rate [60/1 exactly 60 fps]
[2026-11-04 15:57:21.828]: Info: 
[2026-11-04 15:57:21.829]: Info: // Ignore any errors mentioned above, they are not relevant. //
[2026-11-04 15:57:21.829]: Info: 
[2026-11-04 15:57:21.829]: Info: Found H.264 encoder: h264_amf [amdvce]
[2026-11-04 15:57:21.829]: Info: Found HEVC encoder: hevc_amf [amdvce]
[2026-11-04 15:57:21.829]: Info: Starting system tray
[2026-11-04 15:57:21.829]: Info: [libvirtualhid] initialized windows-umdf backend
[2026-11-04 15:57:21.829]: Info: System tray thread initialized successfully
[2026-11-04 15:57:21.830]: Info: No main thread features enabled, skipping event loop
[2026-11-04 15:57:21.830]: Info: System tray thread started
[2026-11-04 15:57:21.834]: Info: Configuration UI available at [https://localhost:47990]
[2026-11-04 15:57:21.875]: Info: Qt: QtTrayMenu: using Qt style "windowsvista"
[2026-11-04 15:57:21.941]: Info: System tray created
[2026-11-04 15:57:22.585]: Info: Registered Sunshine mDNS service
[2026-11-04 15:58:17.592]: Info: Opening UI from system tray
[2026-11-04 15:58:17.608]: Info: Resolved user-provided command 'https://localhost:47990' to 'C:\Program Files\WindowsApps\Mozilla.Firefox_157.0.0.0_x64__n80bbvh6b1yt2\VFS\ProgramFiles\Firefox Package Root\firefox.exe -osint -url "https://localhost:47990"'
[2026-11-04 15:58:17.613]: Info: https://localhost:47990 running with PID 37492
[2026-11-04 15:58:17.613]: Info: Opened url [https://localhost:47990]
[2026-11-04 15:58:29.093]: Info: Opening UI from system tray
[2026-11-04 15:58:29.108]: Info: Resolved user-provided command 'https://localhost:47990' to '"C:\Program Files\Mozilla Firefox\firefox.exe" -osint -url "https://localhost:47990"'
[2026-11-04 15:58:29.112]: Info: https://localhost:47990 running with PID 32296
[2026-11-04 15:58:29.113]: Info: Opened url [https://localhost:47990]
[2026-11-04 15:58:33.479]: Info: Web UI: [127.0.0.1] -- not authorized
[2026-11-04 15:58:47.459]: Info: [libvirtualhid] initialized windows-umdf backend
[2026-11-04 15:58:50.370]: Info: [libvirtualhid] initialized windows-umdf backend
[2026-11-04 15:58:50.378]: Info: [libvirtualhid] initialized windows-umdf backend
[2026-11-04 15:58:55.833]: Info: [libvirtualhid] initialized windows-umdf backend

Online logs

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