In this article, we shall discuss ‘SCVMM setup Error 10421: Fix VMM Service Account conflict”. System Center Virtual Machine Manager (SCVMM) is part of the System Center suite and helps to provide a unified management experience across on-premises, service provider, and the Azure cloud. Please, see SCVMM setup Fails: Fix Missing Windows ADK Deployment Files, and how to Integrate Hyper-V [SCVMM] with Veeam Recovery Orchestrator.

Note: If you install SCVMM using a local or non-domain account, you must manually create a Service Principal Name (SPN) for the VMM service to enable proper Kerberos authentication and communication with Hyper-V hosts and other managed resources.

Note: According to Microsoft, If the account installing SCVMM does not have permission to register the Service Principal Name (SPN) in Active Directory, setup will complete with a warning. If the SPN isn’t registered, VMM consoles on other computers cannot connect to the management server and you won’t be able to deploy a Hyper‑V host to bare metal via VMM.

Also, see how to Create local Backup Repository and Add HyperV to VBR Inventory, how to upgrade Windows Admin Center from v2411 to v2511, and “how to fix The Group Policy settings for BitLocker startup options are in conflict and cannot be applied“.

Why was the error prompted?

Having explained some of the prerequisites to avoid further errors, we will discuss and focus on the current error 10421.

The error “The Specified Account cannot be the same as the VMM service account” occurs because. SCVMM prohibits using the identical domain account for both the VMM service (under which VMMService runs). This is due to security isolation and the need for separation to prevent privilege escalation/abuse during impersonation.

Please, see How to reset Microsoft 365 User Password, how to fix Inbound connection Error: Failed to Perform Scheduled Replication [Part 2], and how to license Veeam Enterprise Manager and Add VBR Servers.

Fix SCVMM setup Error 10421

To fix this, embark on the steps discussed here “Integrate Hyper-V: Install System Center Virtual Machine Manager“. This can be done via the Fabric or VM and Services item from the VMM console.

In the resource location, select “Windows Server Computers in a Trusted Directory domain” and click Next.

Next, specify a new credential for a domain account that has administrative permissions on all hosts that you want to add.

Enter Credentials — It is not supported to change the identity of the Virtual Machine Manager service account after installation. This includes changing from the local system account to a domain account, from a domain account to the local system account. Or changing the domain account to another domain account. To change the Virtual Machine Manager service account after installation. You must uninstall VMM (selecting the Retain data option if you want to keep the SQL Server database). And then reinstall VMM by using the new service account

As you can see below, the new Hyper-V integration is 50% complete.

Clicking on the recent job, we can see the new status percentage and task sequences as shown below.

The add virtual machine host has completed with some warnings. This can be disregarded as it does not relate to my environment. Also, ensure the recommended actions are performed as directed.

View VM Properties

You can drill further into each VM details as shown below.

Take “TechDC02” for example. Below are the VM details.

Also, see the VM properties for this VM machines. You can view more information here.

I hope you found this article on how to resolve “SCVMM setup Error 10421: Fix VMM Service Account conflict”. Please, feel free to leave a comment below.