Configure Veeam Proxy and Repository Correct.

To protect Veeam proxy and backup repository against ransomware, it is recommended that these are not part of an AD domain.

First Upgrade VMware Tools in VM

https://packages.vmware.com/tools/esx/latest/windows/x64/index.html

Disable UAC in the VM (Win2012 and Win2016) by this key
If you use built-in Administrator account, you needn't disable UAC.

By the way, If you want to resolve Veeam RPC issue you need to enable Administrative share ADMIN$ by this key

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system]

"EnableLUA"=dword:00000000

https://www.veeam.com/kb1788

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system]

"LocalAccountTokenFilterPolicy"=dword:00000001