Windows 11 Update Issues: Every Known Bug and Fix (2026)

If your Windows 11 PC has been acting strange lately, you are not imagining it. The August and September 2026 updates introduced more bugs than usual, and Microsoft has been fixing them one at a time. This page tracks every confirmed issue, what caused it, whether it is fixed, and exactly what to do if you are affected.

Quick Answer

• Most bugs came from two updates: KB5120998 (August 27) and KB5124008 (September 8)
• Most issues are already fixed through later updates
• Three issues are still open: black screen after sign-in, domain sign-in failures, and some USB audio problems
• Find your symptom below and jump straight to the fix

Currently Open Issues

These do not have a full fix yet, only workarounds.

Black screen after signing in

Status: Not fully resolved, workaround available

Since the August 27 update, some PCs show a black screen after sign-in instead of loading the desktop. Microsoft says this mostly affects Azure Virtual Desktop machines using FSLogix, not typical home PCs, but if it happens to you:

1. Press Ctrl + Shift + Esc to open Task Manager
2. Click Run new task
3. Type explorer.exe and press OK

Your desktop should load. This does not fix the underlying issue, just gets you back into Windows for that session.

Domain sign-in failures on work PCs

Status: Not fully resolved, workaround available

Some work or school computers connected to an on-premises domain may show a “trust relationship” error after signing in, even with the correct password. This is caused by a Windows security feature called Machine Identity Isolation being enabled on domain networks that do not yet support it.

If you manage IT for an organization and hit this, Microsoft’s fix is to disable Machine Identity Isolation through whichever method was used to turn it on (Intune, Group Policy, or the registry), then run this command in PowerShell to reset the connection:

Test-ComputerSecureChannel -Repair -Credential (Get-Credential)

Regular home users are very unlikely to see this one.

Some USB audio devices still have no sound

Status: Partially resolved

After the September update, some USB Audio Class 1.0 devices stopped working, showing a “Code 10” error or producing no sound. Microsoft’s out-of-band update on September 14 fixed the multichannel and 3D audio version of this bug, but devices with no sound at all, or unresponsive volume controls, are still waiting on a full fix. If your specific USB audio device stopped working after this, try switching it to 2-channel stereo mode as a temporary fix.

Fixed Issues

These are already resolved if you install the latest update.

Remote Desktop Services (RDS) becoming unstable
Fixed by the emergency update on September 14. Full details in our KB5129195 guide.

Hyper-V shared folders missing in Linux virtual machines
Also fixed in that same September 14 update, covered in the same KB5129195 guide.

File History not backing up files
Fixed in the optional September 22 update. See our full File History fix guide if you’re still seeing this.

Teams and Outlook failing to open on ARM devices
Affected devices like the Surface Pro 11 and Surface Laptop 7 after the August update. Fixed in the September 8 update.

Desktop background turning solid black
Some PCs lost their custom wallpaper and reverted to a plain black background after the August 27 update. Fixed September 8.

Mouse cursor and animation settings resetting
Affected non-English Windows installations after the August 27 update. Fixed September 8.

False “Microsoft Defender Antivirus is turned off” warnings
Defender was working fine, the notification itself was wrong. Fixed through a Defender update on September 17, separate from a Windows update.

Games crashing due to RGB lighting software
Games like ARC Raiders and THE FINALS were crashing due to a conflict with certain RGB peripheral drivers. Microsoft resolved this by blocking the specific problem driver.

Bugs Not Officially Listed by Microsoft

A few issues have been widely reported by users and covered by tech outlets but have not appeared on Microsoft’s own official issues page as confirmed bugs:

• HP laptops experiencing BIOS corruption, and Lenovo laptops with random charging failures, both traced back to the August 11 update. Full details and fixes are in our KB5121003 guide.
• AMD graphics driver crashes and black screens after the September update. Microsoft has not published an official fix for this one yet.

How to Check What’s Currently Installed on Your PC

1. Go to Settings
2. Click System
3. Click About
4. Check the OS Build number under Windows specifications

Compare this against our running list of the latest Windows 11 updates to see exactly which update you have and what it included.

General Advice If You’re Having Update Problems

• Always check Settings > Windows Update for the latest available update first. Most of the bugs above are already fixed in current updates.
• If a specific feature broke right after an update, search for that exact symptom rather than assuming your PC is broken. Most of these issues are temporary and get patched within days to a couple of weeks.
• Avoid uninstalling security updates unless a bug is seriously disrupting your work, since it removes protection against real security threats along with the bug fix.
• If you’re dealing with a blue screen crash specifically, our Windows 11 blue screen guide covers that separately, and if your PC crashes specifically around sleep or wake, see our Driver Power State Failure guide.

Frequently Asked Questions