Forum Discussion
Is this the Microsoft Windows Application Compatibility fix Database?
My Windows 11 25H2 laptop has an application called "Microsoft Windows Application Compatibility fix Database" that inexplicably appeared in "Settings" → "Applications". It was installed around 4 PM today; I didn't click on any applications, it just suddenly appeared. Does anyone know what this application is? Its location is C:\Windows\AppPatch, and the modification date has also changed.
3 Replies
This a new hotfix rolling out to fix driver issues caused by the August 2026 Monthly Update, if you have specific games which depend on the inpoutx64.sys driver.
Resolution: This issue is resolved by a block that prevents the inpoutx64 driver from loading. The block targets devices with this specific driver enabled and the game ARC Raiders installed. This resolution disables the inpoutx64 driver and displays a message window with information about the disablement. Following this message, the game will launch as normal.
This resolution is propagating automatically to Windows consumer and business devices that are not managed by IT departments, and a device restart is required. Please note that it might take up to 24 hours starting from August 26, 2026, 6 PM PT for this resolution to reach all affected devices. The driver block will also be included in the September 2026 Windows security updates and subsequent releases.
My laptop uses Windows 11 25H2. Before installing KB5101684, the file history functioned correctly. In "Control Panel → All Console Items → File History," the "Last Backup" time was updated correctly whenever a file was successfully backed up to the D: drive.
However, after installing KB5101684 on July 29, 2026, problems began to occur:
Files can still be backed up to the D: drive normally.
The "Last Backup" time in "File History" fails to update correctly.
Newly created or saved Word documents, images, videos, etc., still show "No previous version available" in "Properties → Previous Versions."
Even more worryingly, my Windows 10 22H2 desktop computer also started experiencing similar file history synchronization issues after installing KB5120249 on August 12, 2026.
interesting, it had also appeared to me.
I uninstalled it - no idea what it is.
