Hi @FOCUS11 -

Welcome to the Community! Well, the message you shared pretty much tells you the issue 

You didn’t really share what task/process you’re trying to do. Can you share explicitly what you’re attempting to do? What is your Veeam setup?

Thanks.

Exactly, it’s not supported. We only support Hyper-V in a Windows Server OS to backup VMs:

 

• Microsoft Windows Server 2022

• Microsoft Windows Server 2019
• Microsoft Windows Server 2016
• Microsoft Windows Server 2012 R2
• Microsoft Windows Server 2012

https://helpcenter.veeam.com/docs/backup/hyperv/system_requirements.html?ver=120#hyper-v-off-host-backup-proxy-hyper-v-host-as-backup-proxy

Was just about to say this and if you need to back up Windows 11 with Hyper-V then you need to use the Agent for it to get the backup to work.

do you have plan to support windows 11 client OS to backup?

Probably best to ping the Product Managers over in the Forums to see what they’re outlook is for that question (if Wesley doesn’t know).

OK, if use the Agent for backup, can I backup the vms? how

The agent gets installed on the VMs to back them up either from the Agent or by managing them in VBR.

oh, you mean I need to install agent on each vm? 

Yes that is how the agent works.

Once installed you can manage from the Agent and use a repository on the Veeam server or have VBR manage the backups for you.

Yes...you’d install in each VM, then backup them up that way. You can follow the Agent Mgmt Guide to do so:

https://helpcenter.veeam.com/docs/backup/vsphere/agent_management.html?ver=120