Microsoft has acknowledged a glitch associated with the KB5070311 preview update, which is causing bright white flashes when users launch File Explorer in dark mode on Windows 11 systems. In a support document released on Monday, the company stated, “After installing KB5070311, you might experience issues when opening File Explorer in dark mode. The window might briefly display a blank white screen before loading files and folders.”
The issue extends beyond just launching File Explorer; it also occurs during various actions such as navigating to or from Home or Gallery, creating new tabs, toggling the Details pane, and selecting ‘More details’ while copying files. As a temporary measure, Microsoft recommends that users disable dark mode to prevent these disruptive flashes until a resolution is implemented.
Update Features and Ongoing Issues
The oversight in addressing this bug prior to the release of the KB5070311 optional update is particularly noteworthy, especially since the update was intended to enhance the dark mode experience. Microsoft has introduced several improvements, including refreshed copy, move, and delete dialogs in both default and expanded views. Progress bars and charts have been adjusted to align with the dark theme for improved readability, and confirmation and error dialogs have been standardized for a cohesive appearance.
In addition to the dark mode issue, the KB5070311 update has resolved a bug that caused the explorer.exe process and the taskbar to become unresponsive following certain notifications. Furthermore, it has addressed a known issue related to File Explorer search failures on some SMB (Server Message Block) shares that arose after recent Windows updates.
Looking back, Microsoft had previously confirmed a critical bug affecting File Explorer, the Start Menu, and other essential system components, particularly when provisioning Windows 11 24H2 devices with cumulative updates released since July 2025. Last month, the company also began testing a new optional feature designed to preload File Explorer in the background, aiming to enhance performance and reduce launch times on Windows 11 systems.
