The Windows 11 update KB5025239 has caused a new problem. It affects an essential element of the operating system, the taskbar.
KB5025239 was released as part of Patch Tuesday in April 2023 and targets PCs running Windows 11 22H2. It closes dozens of security holes and fixes bugs. Unfortunately, problems have arisen since it was deployed. So it’s not the first time that this update has been talked about because of the malfunctions. We’ve talked about File Explorer crashes, missing desktop icons, and performance issues.
Windows 11 and KB5025239, errors appear, solutions
A new bug is added to this list. Recent reports indicate an issue with the taskbar’s auto-hide feature. Its job is to automatically hide it to use the maximum space. It also reappears automatically as soon as the mouse pointer moves over the bottom edge of the screen.
Windows 11 and customize taskbar behavior
The option is at this address
Settings > Personalization > Taskbar > Taskbar behavior
Regarding the bug, it affects this functionality, leaving the taskbar visible very often. Fortunately, the situation does not appear to be widespread.
There are also reports of very slow installation. It can get stuck at 5% for several hours while repeatedly getting the message “Installing updates. Please leave your PC switched on”.
Windows 11 and KB5025239 known issues
On the Microsoft side KB5025239 is known to cause problems with explorer.exe. This happens when using third party UI customization apps like ExplorerPatcher or StartAllBack.
Redmond explained
After installing this update or subsequent updates, certain third-party user interface customization applications may fail to start Windows devices. These third-party applications can cause explorer.exe errors that can repeat itself several times in a loop. These known affected personalization applications are ExplorerPatcher and StartAllBack. This type of application often uses unsupported methods to make customizations and hence may produce unexpected results on your Windows device.
KB5025239 can also slow down machine performance. This applies to copying large files (several GB) with a network share via SMB (Server Message Block) but also when copying files locally.