Ensure you are not using a Datacenter key for a Standard installation, as this will fail. Failed Conversion:
If your organization uses a KMS host:
If the KMS host running on an older OS is decommissioned, Windows Server 2012 R2 clients fall into a 180-day grace period. After that, they enter “notification mode” (hourly shutdown reminders, but core server functions continue—unlike desktop OS versions). Windows Server 2012 R2 Standard Build 9600 Product
Check your current edition: DISM /online /Get-CurrentEdition Go to the Activation section in the System