The current Domain Controller is the operations master. To transfer the operations master role to another computer, you must first connect to it. FSMO Roles

 

We are migrating the Domain controllers from Windows Server 2012 R2 to Windows Server 2019. At the migration, I have faced “The current Domain Controller is the operations master. To transfer the operations master role to another computer, you must first connect to it.” the error.

Solution:

Open the Active Directory users and computers console, right-click the icon and then Change Domain controller. 

Note: All the FSMO roles are in DC1 Server

Click on Change and select the option This Domain Controller or AD LDS instance to DC3 (Windows Server 2019). 

Since I am planning to move all the FSMO roles to DC3

Notice the Active directory users and computers are on DC3. Now right-click the domain and then in Operations Masters. To transfer one of the three FSMO roles to another DC, click Change and confirm your action.

Since I transferred the PDC and RID roles using GUI. Now I will transfer other roles using Powershell.
Here is the powershell command I will be using to transfer Schema Master, Domain Naming master and Infrastructure master

Move-ADDirectoryServerOperationMasterRole -Identity “dc3” –OperationMasterRole DomainNamingMaster, SchemaMaster,
InfrastructureMaster –Force

or 

Move-ADDirectoryServerOperationMasterRole -Identity “dc3” –OperationMasterRole 2,3,4

Demote the DC1 after the roles are transferred and Clean up the metadata

 To clean up meta data. Go to Active Directory Sites and services - > Expand Default-First-Site-Name and click on servers
 and select the DC1 which is demoted. Right click and delete it.