Windows 11: Known issues (October 5, 2021)

Windows[German]Windows 11 was officially released by Microsoft on October 5, 2021. With the release of the first version of this operating system, however, Microsoft could not eliminate all known problems from the Insider Preview. So, the first version of Windows 11 has some known issues, which Microsoft has also officially documented on a status page.


Microsoft documents the known issues in the "Known Issues" section on a dedicated Windows 11 status page (listed there as 21H2). 

Windows 11 Status page

The last update of the page was on October 7, 2021. Currently, the following known issues are listed there:

  • Compatibility issues with Intel "Killer" and "SmartByte" networking software;  Compatibility issues have been detected between some Intel "Killer" and "SmartByte" networking software and Windows 11. Devices running the affected software may drop User Datagram Protocol (UDP) packets under certain conditions. This causes performance and other problems with protocols based on UDP. For example, some websites may load more slowly on affected devices than others, and video will stream more slowly at certain resolutions. VPN solutions based on UDP can also be slower. Microsoft is working on a fix and plans to release it in the October Security Update (October 12, 2021).
  • Compatibility issues have been found between Oracle VirtualBox and Windows 11: Microsoft and Oracle have found a compatibility issue between VirtualBox and Windows 11 when Hyper-V or Windows Hypervisor is installed. You may not be able to start virtual machines (VMs) and you may receive an error. Microsoft has imposed a compatibility lock that prevents these devices from installing or being offered Windows 11. Oracle is working on a solution and is expected to release a compatible version of VirtualBox in October 2021.
  • Compatibility issues have been found between Cốc Cốc browser and Windows 11: Compatibility issues have been found between the Cốc Cốc browser and Windows 11. The Cốc Cốc browser may not open and may cause other problems or errors on some devices. Microsoft has imposed a compatibility lock on these devices to prevent them from installing or being offered Windows 11. The issue is currently under investigation.

More details can be found in the linked support articles.

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2 Responses to Windows 11: Known issues (October 5, 2021)

  1. Raphael Groner says:

    Bei vmworld dieser Woche entstand zunehmend mein Eindruck, dass Microsoft HyperV aufgibt zugunsten VMware-Hypervisor, zumindest ist engere Partnerschaft bei Azure &Co. vorhanden.

    English translation: At vmworld this week, I increasingly got the impression that Microsoft is abandoning HyperV in favor of VMware hypervisor, at least closer partnership is in place at Azure &Co.

  2. Yanta says:

    If it has issues don't release it. The world won't stop if M$ doesn't release a buggy OS on the date they said they would. This just shows M$'s complete lack of commitment to users, their lack of transparency and lack of competence in fixing issues in a timely manner.

    The Insider program is never going to be as good as a proper testing/QA group.

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