So far as I know, the Host Machine has to fit the Windows requirements.
Your system from 2012 will not meet the CPU generation requirement (3 years old or newer) and may not meet the TPM requirements.
It may run Windows 10, but Windows 10 came out in 2015, so if the newest version of Windows 10 won't run, then age of machine is likely the reason.
Be sure you have Hardware Virtualization and VT-d enabled for 64-bit systems.
If not all the above, then it is just a bit too old.
If you are able to find an older version of Windows 10, you may be able to get it to install but it may stop updating at some point, and that could be a security risk