MSIX WebView2 ExternalDependency failing to install/update.

Question

We have an MSIX based application that we ship that depends on the Evergreen WebView2 installs, relying instead on the ExternalDependency support to ensure an evergreen install exists.

Some of our users have reported that WebView2 fails to install properly (even though Windows 11 and AppInstaller are fully updated). They get the error message "App Installer failed to install package dependencies. Ask the developer for package Microsoft.WebView2". Some users reported that WebView2 was already installed w/ a suitable version.

Even Viewer has an info entry that says 'Declared namespace ...externaldependencies is inapplicable. It will be ignored during manifest process' (unsure if this is related or not).

The ExternalDependency element in the manifest was taken almost directly from the Microsoft support page for it:

<win32dependencies:ExternalDependency Name="Microsoft.WebView2" Publisher="CN=Microsoft Windows, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" MinVersion="126.0.2592.0" Optional="false"/>

This issue affects a small but non-trivial subset of our users. We are using a AppName.appinstaller file as our primary install mechanism.

Some users could update from an older version of our app that didn't depend on WebView2. This didn't work consistently, though, as some users' WebView2 installs failed on update. Manual install of Evergreen installer seemed to work in some cases, but not all.

Curious to see if anyone else has seen this or what steps I can take to further troubleshoot/reproduce. My team has not been able to reproduce on any of our machines locally. We'd definitely prefer using WebView2 via the evergreen installer to rolling the fixed version bundled in.