The first Windows update of the year causes authentication problems with Azure Virtual Desktop and Windows 365.
The first security update of 2026 is causing headaches at Microsoft, after users reported problems logging in and connecting via the Windows App to Azure Virtual Desktop and Windows 365.
What goes wrong?
According to Microsoft, the security update of January 13, 2026, can lead to errors when entering login credentials during Remote Desktop connections. As a result, in some cases, it is no longer possible to open virtual desktops via the Windows App. Users see a “Cannot log in” message when connecting.
The problem appears to be widespread and affects virtually all supported Windows versions, from Windows 10 Enterprise LTSC 2016 to Windows 11 25H2. Windows Server editions between 2019 and 2025 are also affected.
Fix on the way
Microsoft advises, for the time being, to switch to the Remote Desktop Client or the web version of the Windows App. Removing the update is also possible, but that means that important security patches will be lost. For many organizations, this is not a desirable option.
Microsoft confirms that it is working on an update that should solve the problem. In addition, a temporary fix should already be available via Known Issue Rollback, although it has not yet been officially shared. Until then, the impact remains particularly significant for companies that have switched to the Windows App.