Microsoft's monthly Patch Tuesday updates for Windows are usually meant to fix problems, but that isn't always the case. The January's updates caused a few problems for businesses. A bug that broke certain kinds of VPN connections was the most serious bug for people still dealing with remote work. After acknowledging the problem on its known issues page, Microsoft has provided fixes for this and other issues.
According to Microsoft's documentation and reporting from Bleeping Computer, the issues with the VPN connection in Windows 10, Windows 11, and Windows server versions in 2016 affected "ipSEC connections which contain a Vendor ID," as well as L2TP and IKE connections in Windows 10, Windows Third-party VPNs clients that use these kinds of connections could also be affected by the error.
The latest round of Patch Tuesday updates caused some problems for Windows server, including failed boots for Hyper-V virtual machines and unexpected restarts for domain controllers. These problems have been solved by other patches, but not before causing problems for IT admins.
There was a problem that caused ReFS-formatted drives to not show up at all. Microsoft blamed the problem on the "unsupported" use of ReFS on removable drives. The consumer versions of Windows supported the ReFS filesystem for a few years, but Microsoft removed the ability to create drives a few years ago.