[Problem/Bug]: WebView2 invoked by SearchHost.exe triggers KnownFolders API access denied errors on multiple system folders

What happened?

SearchHost.exe launches msedgewebview2.exe to render parts of the Windows Search UI. During initialization, WebView2 attempts to verify known folders using the KnownFolders API. It probes multiple system-level folders including, but not limited to:

• C:\ProgramData
• C:\Users<username>
• C:\Users<username>\AppData\Roaming
• C:\Users<username>\Desktop
• C:\Users<username>\OneDrive
• C:\Users<username>\OneDrive\Desktop
• C:\Windows\system32\config\systemprofile\Desktop
• C:\Windows\system32\config\systemprofile\Favorites

These attempts fail with error 0x80070005 (Access Denied), resulting in repeated Event ID 1002 warnings in the Microsoft-Windows-KnownFolders API Service log. The process runs under a restricted context (likely AppContainer or similar ig) and these folders are protected by default ACLs. The access attempts are unnecessary and noisy and usually happen on boot, especially since the folders are obviously present and not misconfigured.

Importance

Moderate. The system is affected by log spam and unnecessary folder probes, but functionality remains usable.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

140.0.3485.54

SDK Version

N/A (not using SDK directly)

Framework

Native

Operating System

Windows 11

OS Version

26100.5074

Repro steps

1. Open Windows Search (Start menu or taskbar)
2. Observe that SearchHost.exe launches msedgewebview2.exe (in Sysinternals Procmon)
3. Check Event Viewer → Applications and Services Logs → Microsoft → Windows → KnownFolders → Operational
4. Multiple Event ID 1002 entries appear with:
   • hrError: 0x80070005
   • FolderId: varies (e.g., ProgramData, Users, etc)
   • Path: varies across protected system folders

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

No, this never worked

Last working version (if regression)

N/A