Microsoft’s monthly “Patch Tuesday” updates are a cornerstone of its Windows maintenance strategy, delivering security fixes and system improvements on the second Tuesday of each month. While these updates are intended to improve reliability, they occasionally introduce new issues.
That appears to be the case for the December 2025 Windows 11 update, KB5072033, which has generated multiple user reports following its release.
According to reports highlighted by Windows Latest, the KB5072033 patch does not affect all systems, but a growing number of users have encountered a range of problems after installing it. These issues vary in severity, from visual inconsistencies to functionality disruptions, prompting renewed scrutiny of the update.
Dark Mode Improvements Remain Incomplete
One of the goals of KB5072033 was to further refine dark mode in Windows 11, particularly in areas where light-colored interface elements still appeared unexpectedly. Microsoft had previously acknowledged an issue where File Explorer displayed brief white flashes when opened in dark mode.
The December update partially addresses this problem. Users report that the white flashes no longer appear when opening Gallery or Home views, nor when File Explorer is already running in the background. However, the issue persists when opening new tabs within File Explorer, where a noticeable white flash can still occur. While largely cosmetic, the unfinished fix suggests that consistency in dark mode for Windows 11 remains a work in progress.
VPN Connectivity Issues in Windows Subsystem for Linux
A more serious issue linked to KB5072033 affects the Windows Subsystem for Linux (WSL). Microsoft has acknowledged that updates released after October 28, 2025—including this December patch—can disrupt networking in specific WSL configurations.
The problem occurs when WSL is set to use mirrored networking mode, which allows it to share Windows’ network configuration. In this setup, some third-party VPN applications fail to function correctly after the update. Affected users report that WSL loses network access and displays a “Do not route to host” error when a VPN connection is active.
Microsoft has confirmed the bug and stated that it primarily impacts enterprise and advanced configurations. Notably, the issue does not affect systems running Windows Home or Pro editions. The company says it is investigating the cause, but a fix is not expected before January 13, 2026.
A Mixed Update Overall
Despite these issues, KB5072033 is not widely regarded as a failed update. Many users report stable performance and no critical issues, making it more reliable than some previous Windows 11 patches. However, the lingering dark mode glitches and the WSL networking bug highlight ongoing challenges in maintaining consistency across Windows’ expanding feature set.
For now, affected users may need to rely on temporary workarounds or wait for a follow-up patch in early 2026. As with many Patch Tuesday releases, KB5072033 underscores the balance Microsoft must strike between rolling out improvements and avoiding unintended side effects.
