Microsoft's monthly Patch Tuesday updates for Windows are generally intended for fix problems, but this is not always the case. January updates, released last week, caused a handful of issues for businesses in particular. The most serious, especially for people still dealing with pandemic-powered telecommuting setups, was a bug that broke certain types of VPN connections. Microsoft has provided fixes for this and other issues from today, a few days after acknowledging the issue on the Known Issues page.
According to Microsoft documentation and reporting from Bleeping Computer, the issues with the VPN connection "IPSEC connections that contain a vendor ID", as well as L2TP and IPSEC IKE VPN connections in Windows 10, Windows 11 and Windows Server versions 2022, 20H2, 2019, and 2016. Windows' built-in VPN client seems to be the most affected, but third-party VPN clients that use these kinds of connections may also run into the error.
The latest round of Patch Tuesday updates also caused some issues for Windows Server, including unexpected reboots for domain controllers and failed booters for Hyper-V virtual machines. These issues have all been resolved by other out-of-band patches, though not until they have caused problems for besieged IT administrators.
Microsoft has also fixed an issue that caused ReFS-formatted drives to not appear at all or turn out to be raw, unformatted disks. Microsoft has also resolved this issue, though not before blaming the issue on "unsupported" use of ReFS on removable drives. The ReFS file system was supported in the consumer versions of Windows for a few years, although Microsoft removed the option to create ReFS drives a few years ago and limited it to servers and enterprise versions of Windows.