Sunshine-Windows-AMD64-installer.msi error, due to which any new version cannot be installed over the previous one.

[termuxxfceuser]

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?

None

Describe the Bug

Dear developers! About a few pre-release versions ago, you made an error in the logic of the msi-installer Sunshine-Windows-AMD64-installer.msi.
Whenever you try to install a newer version of the Sunshine application, this installer gives an error that it is impossible to install a newer version of the application, since the newest version is supposedly already installed.
This happens because you are using incorrect numbering of new builds of pre-release versions and an incorrect algorithm for generating and subsequently recording the hidden installation identifier of the MSI application package in the Windows registry!

As a result, until such incorrect identifiers are manually removed from the registry, you will not be able to install a newer version.

I even wrote a script in PowerShell, which itself searches for your incorrectly used identifiers and removes them from the Windows registry, after which the ability to safely install any next new versions of your Sunshine application returns.

Please fix this problem with your Sunshine msi installer!

Expected Behavior

No response

Additional Context

No response

Host Operating System

Windows

Operating System Version

Windows 11 25H2 64-bit Pro

Architecture

amd64/x86_64

Package

Windows - msi installer (recommended)

GPU Type

Intel

GPU Model

Nvidia RTX 2000 ADA

GPU Driver/Mesa Version

Latest official Nvidia drivers

Capture Method

None

Apps

Log output

Online logs

No response

[ReenigneArcher]

What version are you trying to install?

What I suspect is you are actually installing a PR version, not a pre-release/beta version. PR versions are like 0.0.<PR-NUMBER>, and these will always be lower than any stable or pre-releases.

Pre-releases and stable releases use the same versioning and are calendar based. There is no way for a pre-release to have a lower version than a previous version.

[termuxxfceuser]

What version are you trying to install?

What I suspect is you are actually installing a PR version, not a pre-release/beta version. PR versions are like 0.0.<PR-NUMBER>, and these will always be lower than any stable or pre-releases.

Pre-releases and stable releases use the same versioning and are calendar based. There is no way for a pre-release to have a lower version than a previous version.

It's strange that you didn't even try to understand what the bug report was about!

Let's go in order:

1. The current release is v2026.516.143833.
2. The two most recent pre-releases (strictly chronologically) have versions v2026.713.170739 and v2026.715.205118.
   Note that the pre-release builds are HIGHER than the release builds!

However, if you first install v2026.713.170739 on a completely clean computer and then try to update it to the CURRENT, latest pre-release v2026.715.205118, you won't be able to. You'll get an error indicating that you supposedly already have the latest version installed.

In this situation, you can install the latest pre-release version v2026.715.205118 only if you remove the faulty identifiers from the previous installation from the Windows registry! Even simply uninstalling v2026.713.170739 won't help (since uninstalling the application will NOT remove the faulty identifiers from the registry).
And once these identifiers are manually removed, you can install the current pre-release version v2026.715.205118 without any problems.

This is a clear and obvious error you made when compiling the MSI installer!

[termuxxfceuser]

Here's my PowerShell-script that removes invalid identifiers from the Windows registry for previous installations.
This script clearly explains the problem:

[Console]::OutputEncoding = [System.Text.Encoding]::UTF8

# Ensure the script is running with administrative privileges
if (-not ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
    Write-Warning "Please run this script as an Administrator!"
    Exit
}

Write-Host "Starting aggressive cleanup of all hidden Sunshine installer keys..." -ForegroundColor Cyan

# The specific UpgradeCode for Sunshine installer
$UpgradeCode = "512A3D1B-BE16-401B-A0D1-59BBA3942FB8"

# Convert the UpgradeCode into the compressed/packed GUID format used by Windows Installer
$CleanUC = $UpgradeCode.Replace("-","")
$PackedUC = ($CleanUC[7..0] -join "") + ($CleanUC[11..8] -join "") + ($CleanUC[15..12] -join "") + ($CleanUC[17..16] -join "") + ($CleanUC[19..18] -join "") + (0..5 | ForEach-Object { $CleanUC[(21+$_*2)..(20+$_*2)] -join "" })

# Registry paths where installer relations and product details are stored
$RegistryPaths = @(
    "HKLM:\SOFTWARE\Classes\Installer\UpgradeCodes\$PackedUC",
    "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UpgradeCodes\$PackedUC",
    "HKLM:\SOFTWARE\Classes\Installer\Products",
    "HKLM:\Software\Microsoft\Windows\CurrentVersion\Installer\UserData"
)

# 1. Remove the UpgradeCode relationship branches first
foreach ($Path in $RegistryPaths[0..1]) {
    if (Test-Path $Path) {
        Write-Host "Hidden UpgradeCode relation found. Removing..." -ForegroundColor Yellow
        Remove-Item -Path $Path -Recurse -Force -Verbose
    }
}

# 2. Search for phantom products by the keyword "Sunshine" in all hidden subkeys
$TargetGUIDs = @()

# Using CMD 'reg query' because it bypasses some PowerShell registry provider limitations with system-hidden keys
$RegSearch = reg query "HKLM\SOFTWARE\Classes\Installer\Products" /s /f "Sunshine" 2>$null
if ($RegSearch) {
    foreach ($Line in $RegSearch) {
        if ($Line -match "HKEY_LOCAL_MACHINE\\SOFTWARE\\Classes\\Installer\\Products\\([A-F0-9]{32})") {
            $TargetGUIDs += $Matches[1]
        }
    }
}

$TargetGUIDs = $TargetGUIDs | Select-Object -Unique

if ($TargetGUIDs.Count -eq 0) {
    # Additional backup check in UserData in case it was a Per-User installation
    $RegSearch2 = reg query "HKLM\Software\Microsoft\Windows\CurrentVersion\Installer\UserData" /s /f "Sunshine" 2>$null
    if ($RegSearch2) {
        foreach ($Line in $RegSearch2) {
            if ($Line -match "Products\\([A-F0-9]{32})") {
                $TargetGUIDs += $Matches[1]
            }
        }
    }
}

$TargetGUIDs = $TargetGUIDs | Select-Object -Unique

if ($TargetGUIDs.Count -eq 0) {
    Write-Host "No keys found. If the installer error persists, Sunshine might have been installed under a different user account (Per-User)." -ForegroundColor Red
    Exit
}

# 3. Purge the discovered packed Product GUIDs from the system
foreach ($PackedGUID in $TargetGUIDs) {
    Write-Host "Found hidden phantom Product Code: $PackedGUID" -ForegroundColor Yellow
    
    # Remove from Classes/Installer/Products
    $ClassPath = "HKLM:\SOFTWARE\Classes\Installer\Products\$PackedGUID"
    if (Test-Path $ClassPath) {
        Remove-Item -Path $ClassPath -Recurse -Force -Verbose
    }
    
    # Remove from UserData branch
    $UserDataSearch = Get-ChildItem -Path "HKLM:\Software\Microsoft\Windows\CurrentVersion\Installer\UserData" -Recurse -ErrorAction SilentlyContinue | Where-Object { $_.PSChildName -eq $PackedGUID }
    foreach ($UD in $UserDataSearch) {
        Remove-Item -Path $UD.PSPath -Recurse -Force -Verbose
    }
}

Write-Host "Cleanup completed successfully!" -ForegroundColor Green

[ReenigneArcher]

Let's do an experiment with AMD64 msi installer.

Starting with a PR version installed:

Updating to v2026.516.143833 succeeded:

Updating to v2026.713.170739 succeeded:

Updating to v2026.715.205118 will replicate your scenario; however manually uninstalling the v2026.713.170739 version did allow me to install v2026.715.205118. I did not have to do anything in the registry.

There is nothing between any of these versions that changed how versioning is done.

[ReenigneArcher]

The upgrade code guid is not the problem, it's that our version numbers are not completely compatible with what msi expects (8 bit, 8 bit, 16 bit). But clearing the guid from the registry will temporarily resolve it since then the new installer doesn't have anything to compare to.

Anyway, I'm working on a fix.