Issue with Major Upgrade in Per-User Installations Using WixUI_Advanced

[Biktop]

Question

Hello,

I’m encountering an issue with major upgrades in per-user installations using WiX Toolset v6.0.1.

I have a fairly simple MSI project built with the WixUI_Advanced template. This allows the user to choose between per-user or per-machine installation scopes and to select the target installation directory.

Everything works as expected—except when performing a major upgrade in per-user mode.

Problem Description

When version 1.0.0 is installed using per-user scope, and then version 1.0.1 is installed also with per-user scope, both versions appear in the “Installed Apps” list (Add/Remove Programs). This does not happen when using per-machine installs—the upgrade behaves as expected there.

Investigation So Far

My investigation points to the FindRelatedProducts and AppSearch actions executing too early in the installation sequence.

From what I can tell:
• The default value of ALLUSERS is 1 or 2 before the InstallScopeDlg is displayed.
• Because of this, the upgrade detection logic is run before the actual user selection of the installation scope is known.
• As a result, when upgrading in per-user mode, the installed product is not found, and a new one is added instead of replacing the old version.

Questions

1. Is there a recommended way to defer the FindRelatedProducts action until after the InstallScopeDlg runs and the actual ALLUSERS value is known?
2. Has anyone successfully implemented a workaround or patch for this scenario?
3. Could this be considered a bug or limitation in the current WixUI_Advanced behavior?

Additional Context

• WiX Toolset version: 6.0.1
• UI Template: WixUI_Advanced
• Install scope switch: enabled via InstallScopeDlg
• Major upgrade setup: Standard approach using UpgradeCode, FindRelatedProducts, and RemoveExistingProducts.

Any insights, workarounds, or guidance would be greatly appreciated!

Open Source Maintenance Fee

• I (or an organization I'm a member of) pay the Open Source Maintenance Fee by sponsoring the wixtoolset project because I support the maintainers.

[robmen]

I feel like there is already an issue opened on this about WixUI_Advanced.