When a replication job runs for the first time, Veeam Backup & Replication creates a VM replica on the target host. This VM replica has the same configuration as the original VM. If the version of the original VM hardware is higher than the versions supported on the target host, the VM replica cannot be created.
You can check the hardware version of the original VM in vCenter. For this, select the VM and open the Summary
tab. In the VM Hardware
section, you can see the following information:
The full list of ESXi/ESX hosts and compatible VM hardware versions is available in this VMware KB article.