Microsoft's April 2019 security updates and monthly rollups are turning into a bigger problem than originally known.
Last week Windows 7 users with Sophos and Avast antivirus began reporting problems after installing Microsoft's April 9 updates.
As ZDNet reported, users suggested that Windows 7, Windows 8.1, Windows Server 2008 R2, and Windows Server 2012 were failing to boot after installing the security-only and monthly rollup updates.
Despite user reports of boot problems affecting Avast users, Microsoft at the time only confirmed problems affecting Sophos users.
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And while there were some reports of similar issues and slowdowns affecting Windows 10 after installing the April 2019 updates, they were not widespread and not necessarily caused by Microsoft's April software updates.
Microsoft has now confirmed that there is an antivirus clash that affects Windows 10 version 1809 but only in relation to ArcaBit, a little-known Polish antivirus vendor.
"Microsoft and ArcaBit have identified an issue on devices with ArcaBit antivirus software installed that may cause the system to become unresponsive upon restart after installing this update," Microsoft said in update on Saturday to known issues affecting Windows 10 1809.
Microsoft has also identified a problem affecting the rename operation in Cluster Shared Volume (CSV) folders. It will fix that issue in a future update. This issue affects Windows 10 and Windows 8.1 and Windows Server 2012 but not Windows 7.
"Certain operations, such as rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, 'STATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)'. This occurs when you perform the operation on a CSV owner node from a process that doesn't have administrator privilege."
"Microsoft has temporarily blocked devices from receiving this update if Avira antivirus software is installed. We are presently investigating this issue with Avira and will provide an update when available," Microsoft notes.
The company also confirmed boot problems affecting Avast for Business, Avast CloudCare, and AVG Business Edition on Windows 7. Avast has released 'emergency updates' to fix this problem for customers and details the procedures to resolve problems in a support note.
"Microsoft and Avast have identified an issue on devices running Avast for Business, Avast CloudCare, and AVG Business Edition antivirus software after you install this update and restart. Devices may become unresponsive at the login or Welcome screen. Additionally, you may be unable to log in or log in after an extended period of time," Microsoft explains.
More on Windows updates
- Windows 7 problems: Microsoft blocks April updates to systems at risk of freezing
- Windows 10 1809's second update finally arrives, trailing 1803's patch by 2 weeks
- Microsoft is ready to move Windows 10 Fast Ring testers to build 20H1
- Microsoft is making big Windows 10 update changes starting with the May 2019 release
- Windows 10 1903 update nears: Microsoft removes another barrier to its release
- Microsoft to Windows 10 users: Are we doing a good job warning you on update bugs?
- Windows 10 1809, 1803: Microsoft confirms new bug in cumulative update
- Microsoft: You really should bookmark this Windows 10 update history page
- How to turn features on and off in Microsoft Windows 10 from the Control Panel TechRepublic
- How to reinstall updates that Windows 10 automatically uninstalled CNET