KB5063878: Microsoft Confirms UAC Changes Breaking App Installs on Windows 10 & 11

Microsoft’s August 2025 security update (KB5063878) has introduced a notable security change that affects how User Account Control (UAC) behaves during Windows Installer (MSI) repair operations.

The update enforces a requirement for administrator credentials whenever MSI repair or related tasks are triggered, closing off a vulnerability tracked as CVE-2025-50173.

With this new enforcement, standard users may encounter UAC prompts in several scenarios. These include running MSI repair commands, launching certain Autodesk applications like AutoCAD or Civil 3D, and installing apps that configure themselves per user.

In some cases, such as Office Professional Plus 2010 installations, standard users will hit Error 1730 if the app attempts a repair without displaying a prompt. Microsoft recommends running applications as an administrator whenever possible.

IT admins who cannot grant users admin rights can use a special Group Policy through Known Issue Rollback (KIR) to mitigate the issue across supported platforms. This option is available for Windows Server 2025, Windows Server 2022, Windows 11 (22H2, 23H2, 24H2), and Windows 10 (21H2, 22H2), among others. Admins are advised to avoid disabling UAC or other security features as a workaround.

The company has confirmed that it is actively working on a longer-term solution. A future Windows update will allow IT admins to permit specific applications to perform MSI repair operations without triggering UAC prompts, striking a balance between usability and security.

Alongside the UAC change, the KB5063878 update has annoyed plenty of users due to SSD failures and streaming issues. Microsoft has recently clarified that these hardware issues are not tied to the August update. SSD manufacturer Phison also confirmed the same, noting that it couldn’t reproduce the SSD failure issue after installation of the update.