Windows 11 KB5124008 was anticipated to be a significant enhancement, promising the return of beloved features from the Windows 10 era, such as a movable taskbar and a resizable Start menu. However, the reality has proven to be less than ideal, as users are encountering a range of issues following its release on September 8. Microsoft has acknowledged that this update disrupts WSL-based applications and Remote Desktop sessions, but our findings reveal additional complications, including problems with File History backups and instability in Explorer.exe, leading to system and GPU crashes.
Ironically, these issues surfaced shortly after Microsoft urged users to promptly install updates to mitigate rising AI-assisted security threats. The Microsoft 365 director cautioned against delaying critical quality updates, emphasizing that such delays could leave systems vulnerable to exploitation by malicious actors leveraging AI technology. In response, Microsoft has revised its recommendations, advising users to limit the deferral period for quality updates to less than three days.
Anthropic says Microsoft broke Claude Cowork on Windows 11, and Microsoft admits it
In a recent update, Microsoft confirmed a bug in Windows 11 KB5124008 that disrupts applications utilizing HCS-managed Linux virtual machines, particularly affecting those using Plan9 shared folders. Users of Claude Cowork, who have integrated the app with their preferred folders, are experiencing connectivity issues. Upon installation of the update, many found that their Cowork workspace failed to connect, prompting suggestions to reinstall the desktop app or manually execute commands.
Reports have emerged on platforms like GitHub, indicating that this issue is widespread among Windows users. Our investigations revealed that the September update altered the Plan9/9P filesystem-sharing implementation, leading to rejected connection requests. While Windows can still create the necessary virtual machine, the Linux guest is unable to attach and mount it as expected. Anthropic has acknowledged the bug, stating that it is a result of the Windows update and currently lacks a patch.
Microsoft says Remote Desktop Services (RDS) is broken
Another significant concern stemming from Windows 11 KB5124008 is the malfunctioning of Remote Desktop Services (RDS). This issue primarily impacts enterprises and users who rely on Remote Desktop for their operations. Users have reported frequent connection failures and instability, rendering remote access nearly impossible. Additionally, some have encountered sign-in problems and prolonged loading times during Remote Desktop configuration.
Microsoft has advised affected users to seek support during weekdays or await the next update, which may address these ongoing RDS issues.
Microsoft appears to be investigating Explorer.exe crashes (enterprises are mostly affected)
A particularly troubling bug within Windows 11 KB5124008 is causing some systems to display a black screen upon sign-in, attributed to Explorer.exe failing to launch correctly or crashing shortly thereafter. This issue extends beyond just File Explorer, as Explorer.exe is integral to the desktop, taskbar, and Start menu functionalities. Users have been left with limited options, often resorting to restarting the process through Task Manager.
Microsoft has acknowledged the situation and is actively investigating the reports, particularly those from users operating in virtual desktop environments where profiles are stored in containers. The company has requested memory dumps to assist in identifying the root cause of these issues.
File History backup feature is broken
While Microsoft has yet to officially confirm it, numerous reports indicate a regression in the File History feature following the Windows 11 update. Users have noted that File History fails to recognize any connected external backup drives, rendering the feature ineffective. This built-in backup tool, which is designed to automatically create copies of files and maintain older versions, has been a reliable resource until now.
Despite the lack of official acknowledgment from Microsoft, users have reported that uninstalling Windows 11 KB5124008 restores File History functionality. However, given the critical nature of this update in addressing numerous security vulnerabilities, removing it is not advisable unless absolutely necessary.
Windows 11 KB5124008 is causing issues on some AMD PCs
Reports have also surfaced regarding serious GPU issues on AMD Radeon systems following the installation of Windows 11 KB5124008. Users have experienced driver timeouts, black screens, and system freezes, with some noting that the GPU driver fails to function even after reinstallation. The specific models affected include a range of Radeon GPUs, such as RX 6600, RX 7700 XT, and RX 7900 XTX.
While removing the September update appears to alleviate these issues for some users, the broader implications of this update remain uncertain. As Microsoft continues to investigate, users are advised to proceed cautiously, weighing the importance of security updates against the potential for operational disruptions.
