Well, I installed the English language pack and made it default. Changed region to US and even timezone to PT (and synced with server). Reinstalled sandbox.
Same error.

Also restarted a few times...

Same error here. Tried with Virtual Machine Platform + Hypervisor, no luck. They don't enable them on the tutorial bro67 linked, so I don't think they're needed.
Virtualization enabled on BIOS.
...