Overview
- The optional KB5070311 update causes a brief blank white screen in File Explorer when dark mode is enabled, particularly when opening Explorer, navigating to or from Home or Gallery, creating a new tab, toggling the Details pane, or selecting More details during file copy.
- Microsoft also lists a separate known issue where the password icon on the lock screen becomes invisible, though the password option still works if selected.
- The company says it is working on resolutions but has not provided an estimated delivery date for patches.
- Practical mitigations include uninstalling the preview update or turning off dark mode, and coverage notes third‑party mods as temporary workarounds.
- KB5070311 is a non‑security preview that must be manually installed and was intended to extend dark mode to File Explorer dialogs, alongside fixes for issues such as explorer.exe/taskbar responsiveness and SMB share search failures.