SCCM Upgrade is blocked on Windows Server 2012/2012 R2
If you still have ConfigMgr Site Servers running on Server OS 2012/2012 R2, plan for a server upgrade before SCCM 2403 blocks the upgrade. Starting with version 2403, the SCCM upgrade is blocked in the hierarchy that is running site roles on Windows Server 2012/2012 R2. In simple words, Windows Server 2012 and 2012 R2 operating systems won’t be supported for installing SCCM roles anymore. Recently, Microsoft released Configuration Manager current branch update 2403. One of the prerequisites for installing this update is that you should not have site servers and roles running on Windows Server 2012 or 2012 R2. If you have these unsupported server OS in your setup, the 2403/2409 upgrade will fail. The site servers and roles commonly include distribution points, Management points, servers running SUP role, etc. Configuration Manager administrators should prepare to upgrade their Windows servers to the next supported version, which is 2016, 2019, 2022, or 2025. This allows them to upgrade ...