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Windows 11 KB5070311 Update Addresses File Explorer and Search Issues

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Microsoft has released the KB5070311 optional preview cumulative update for Windows 11, addressing File Explorer freezes, search issues, and other bugs. The update includes 49 changes and is part of the monthly preview updates that precede Patch Tuesday releases. It fixes issues with explorer.exe process responsiveness, SMB share search problems, and LSASS instability. However, the update also introduced a new bug causing bright white flashes when launching File Explorer in dark mode. Microsoft has since fixed this issue with the December KB5072033 Patch Tuesday cumulative update. The update is available for manual installation and updates Windows 11 25H2 and 24H2 devices to builds 26200.7309 and 26100.7309, respectively. Additionally, Microsoft announced there will be no preview update in December 2025 due to minimal operations during the Western holidays, with normal updates resuming in January 2026. Microsoft is still working to fully address the File Explorer white flash issue in dark mode, with the bug fix rolling out to all Windows Insiders in the Beta and Dev channels who install the Windows 11 Build 26220.7961 (KB5079382) and Windows 11 Build 26300.7965 (KB5079385) preview builds. The latest Windows 11 preview builds also add support for voice typing (Windows key plus H) when renaming files in File Explorer and improve reliability when unblocking files downloaded from the internet to preview them in File Explorer. Starting in November, Microsoft began testing an optional Windows 11 feature that preloads File Explorer in the background to improve performance and speed up launch times.

Timeline

  1. 09.03.2026 16:10 1 articles · 23h ago

    Microsoft rolls out fixes for File Explorer issues in preview builds

    The latest Windows 11 preview builds add support for voice typing (Windows key plus H) when renaming files in File Explorer and improve reliability when unblocking files downloaded from the internet to preview them in File Explorer. Starting in November, Microsoft began testing an optional Windows 11 feature that preloads File Explorer in the background to improve performance and speed up launch times.

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  2. 11.12.2025 12:09 1 articles · 2mo ago

    Microsoft releases KB5072033 Patch Tuesday update fixing dark mode flash bug

    Microsoft has released the December KB5072033 Patch Tuesday cumulative update, which includes a fix for the File Explorer white flash issue in dark mode. The update also addresses a known issue that caused network connectivity to be lost on virtual machines after external virtual switches lose their physical network adapter bindings following a host restart. Additionally, it patches Windows PowerShell to warn when scripts use the Invoke-WebRequest cmdlet to download web content, helping prevent the execution of harmful code.

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  3. 02.12.2025 15:39 3 articles · 3mo ago

    KB5070311 introduces File Explorer dark mode flash bug

    The KB5070311 update triggered bright white flashes when launching File Explorer in dark mode on Windows 11 systems. This issue occurred during various actions such as navigating to or from Home or Gallery, creating a new tab, toggling the Details pane, and selecting 'More details' while copying files. Microsoft is still working to fully address this issue, with the bug fix rolling out to all Windows Insiders in the Beta and Dev channels who install the Windows 11 Build 26220.7961 (KB5079382) and Windows 11 Build 26300.7965 (KB5079385) preview builds.

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  4. 02.12.2025 13:19 2 articles · 3mo ago

    Windows 11 KB5070311 Update Released with 49 Fixes

    Microsoft released the KB5070311 optional preview cumulative update for Windows 11, addressing File Explorer freezes, search issues, and other bugs. The update includes 49 changes and is available for manual installation. It updates Windows 11 25H2 and 24H2 devices to builds 26200.7309 and 26100.7309, respectively. Microsoft also announced there will be no preview update in December 2025, with normal updates resuming in January 2026. Additionally, the update introduces a bug causing bright white flashes when launching File Explorer in dark mode, which Microsoft is working to fix.

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Information Snippets

Similar Happenings

Windows Updates Cause RemoteApp Connection Failures in Azure Virtual Desktop

Recent Windows updates, including the November 2025 KB5070311 non-security update and a recent Windows 365 update, are causing RemoteApp connection failures in Azure Virtual Desktop environments on Windows 11 24H2/25H2 and Windows Server 2025 devices. This issue primarily affects enterprise users, leaving full desktop sessions unaffected. The incident began on Tuesday at 19:00 UTC, with users experiencing sign-in failures and intermittent access issues to their Cloud PCs. Microsoft has provided temporary mitigations, including a registry key modification, a Known Issue Rollback (KIR) for Windows Pro and Enterprise devices, and workarounds such as accessing Cloud PCs through the Windows App Web Client or using the Remote Desktop client for Windows. Microsoft is working on a permanent fix but has not provided a timeline.

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Microsoft December 2025 Updates Break Message Queuing Functionality

Microsoft's December 2025 security updates caused Message Queuing (MSMQ) failures across Windows 10 22H2, Windows Server 2019, and Windows Server 2016 systems. The issue arose from security model changes that modified permissions on a critical system folder, leading to errors in MSMQ queues and IIS sites. Affected systems experienced inactive queues, resource errors, and application failures. Microsoft has released an out-of-band update (KB5074976) via Update Catalog to address the issue. The company initially advised enterprise customers to contact support for a temporary workaround, and the update is now available for download.

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Windows 11 24H2 Bug Causes Critical System Component Crashes

Microsoft has confirmed a critical bug in Windows 11 24H2 that causes File Explorer, Start Menu, and other key system components to crash after installing cumulative updates released since July 2025. The issue arises from XAML dependency packages failing to register properly, affecting both regular and non-persistent OS installations. Users experience crashes in essential shell components, leading to partially functional systems. Microsoft is working on a resolution and has provided temporary workarounds.

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Microsoft Releases November and December 2025 Patch Tuesday Updates for Windows 11

Microsoft has fully resolved the Windows 11 'UNMOUNTABLE_BOOT_VOLUME' boot failure issue in the February 2026 Patch Tuesday security update (KB5077181), addressing a problem that left commercial systems unbootable after failed December 2025 updates. The issue, which affected Windows 11 versions 25H2 and 24H2, was initially mitigated by the optional KB5074105 preview update but is now considered fully resolved. Devices that became unbootable before the fix may still require manual recovery or enterprise support. Earlier, Microsoft linked the January 2026 boot failures to failed attempts to install the December 2025 security update, which left systems in an unstable state. The company had also released emergency out-of-band updates to fix an unrelated issue causing Microsoft Outlook to freeze when PST files were stored in cloud services. Prior updates included fixes for gaming performance issues, broken localhost HTTP connections, and Windows Recovery Environment (WinRE) problems, alongside cumulative updates for November and December 2025 introducing new features and addressing security vulnerabilities across Windows 11 versions 25H2/24H2 and 23H2.

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Microsoft Rolls Out Windows Backup for Organizations

Microsoft has expanded the Windows Backup for Organizations feature to support more enterprise devices. The first sign-in restore experience now allows users to restore settings and Microsoft Store apps on first login to a new or reimaged Windows 11 device, extending support to hybrid-managed environments, multi-user device setups, and Windows 365 Cloud PCs. Originally announced in October 2025, Windows Backup for Organizations is designed to simplify backups and facilitate the transition to Windows 11. The feature is available for Entra-joined devices after installing the September 2025 Windows Monthly Cumulative Update. It backs up Windows settings, preferences, and Microsoft Store-installed apps on Windows 10 and Windows 11 systems, and restores them on Windows 11 PCs during device setup. Data is stored in the Exchange Online cloud, with encryption and strict access controls. The feature must be enabled by IT administrators via backup and restore policy settings.

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