Windows 11 January Update Breaks Notepad

Summary

TL;DR Bug Impact: Microsoft’s January 2026 security update KB5074109 broke Windows 11 apps like Notepad and Snipping Tool with error code 0x803f8001. Partial Fix: Microsoft released an emergency patch fixing the app launch bug, but a separate cloud storage issue remains unresolved. Ongoing Issue: Applications continue freezing when saving files to OneDrive or other cloud storage, forcing users to move files locally as a workaround. Microsoft broke several Windows 11 apps with its January 2026 security updates, introducing two separate bugs affecting programs like Notepad and Snipping Tool. Windows 11 users reported dual bugs this week from the same security patch, with Microsoft rolling out emergency fixes that addressed one issue while leaving the other unresolved. Microsoft forum user Kave discovered the problem on Tuesday when trying to access work-related information stored in Notepad. “Getting the error code 0x803f8001 for most my microsoft apps including my Notepad app which has important information and URLS i need for my job. This is getting pretty paralyzing,” Kave wrote in a Microsoft support forum. Multiple Windows applications stopped working, including Notepad, Snipping Tool, Xbox Ally Armoury Crate, Alienware Command Center, and Nitrosense. The errors stem from two distinct bugs introduced by KB5074109, Microsoft’s January 2026 Patch Tuesday security update released on January 13. First Bug Fixed, Second Persists The technical root of the first failure proved more complex than a simple app malfunction. The 0x803f8001 error prevents apps from launching entirely, often accompanied by File system error (-2143322111). The error occurs when the Microsoft Store cannot validate app licenses, typically caused by a corrupted Store cache or temporary Microsoft account sync issues rather than actual data loss. Users initially feared they had lost access to files stored within affected applications, but the underlying data remained intact. This represented a licen...