Known Issue
August updates trigger 0xc0000409 errors on Windows Server 2016
Microsoft says the August 2026 security update may trigger 0xc0000409 errors on Windows Server 2016 systems where the Compatibility Appraiser diagnostic service is enabled. On affected systems, users will see the CompatTelRunner.exe (Compatibility Appraiser Telemetry Runner) process crashing. Microsoft Compatibility Appraiser, which controls CompatTelRunner and is a Windows Compatibility Telemetry component, is a background system […]
Microsoft: Windows Server 2025 changes causing app crashes
Microsoft warned customers last week that they may experience application crashes on some Windows Server 2025 due to recent memory management changes. This known issue affects apps that use Address Windowing Extensions (AWE), a set of extensions that lets an application use more than 4GB of physical memory within a 32-bit virtual address space. “Applications running on […]
Microsoft says some users can’t open the Teams desktop client
Microsoft is working to resolve a known issue that causes delays or blocks some users from opening the Microsoft Teams desktop client on Windows systems. The company acknowledged this known issue (tracked as TM1466820) at 16:45 EDT on Thursday and advised affected customers to work around it by using the web or mobile platforms. “Specifically, when […]
Microsoft: KB5120998 mouse reset bug affects only non-English PCs
Microsoft says a known issue that reverts mouse settings after installing the KB5120998 August 2026 preview update affects only non-English Windows 11 systems. The bug was confirmed Friday, one day after the KB5120998 release, which includes Start menu, taskbar, and Windows search improvements for devices running Windows 11 versions 25H2 and 24H2. According to user reports, mouse […]
Microsoft says KB5120998 Windows update resets desktop settings
Microsoft has confirmed that desktop settings are lost or reset on some Windows devices after installing the KB5120998 August 2026 preview update. Microsoft’s confirmation follows a wave of user reports saying their wallpaper switched to a black background automatically after installing this Windows update. The known issue impacts systems running Windows 11 24H2 and Windows 11 25H2, and it may affect the wallpaper, the desktop […]
Microsoft Teams, Outlook fail to launch on ARM-based Windows PCs
Microsoft is working to fix a known issue that causes crashes and launch failures for Microsoft Teams and New Outlook users after installing updates released since the August 2026 Patch Tuesday. These issues affect only ARM-based Windows devices like the Surface Laptop 7 and Surface Pro 11 that run Windows 11 24H2 or later, and […]
Microsoft asks users to ignore ‘Antivirus is turned off’ errors
Microsoft asked customers this week to ignore incorrect alerts that Defender Antivirus has been turned off after installing the latest Defender updates. Although this issue has been affecting users in the Release Preview Channel of the Windows Insider program since June, it appears Microsoft didn’t notice it until now. The erroneous alerts appear on affected systems in the Windows […]
Microsoft rolls out fix for Windows 11 crashes, gaming issues
Microsoft has started rolling out a permanent fix for a known issue that causes system crashes and gaming issues on Windows 11 devices. On affected PCs, users have also reported games failing to launch and freezing with “EXCEPTION_ACCESS_VIOLATION” errors. When it was first confirmed, Microsoft said that this issue affects games like ARC Raiders, MARVEL Tōkon: Fighting […]
Microsoft shares temporary fix for Windows 11 gaming issues
Microsoft has shared a temporary fix for ongoing gaming issues caused by Windows 11 updates released during the August 2026 Patch Tuesday. On impacted PCs, users reported games crashing or failing to launch, as well as game freezes, “EXCEPTION_ACCESS_VIOLATION” errors, and even unexpected system restarts. When it confirmed it was investigating this known issue on […]
Microsoft: August updates break printing, PDF export in WPF apps
Microsoft has confirmed that .NET Framework updates released as part of the August 2026 Patch Tuesday are breaking printing and PDF export in some applications. In a Windows release health alert seen by GeekFeed, Microsoft says this known issue affects only apps that use the Windows Presentation Foundation (WPF) UI framework, an open-source graphical subsystem […]