Log in to your server as root.  At the server’s command line, type “visudo”.

Scroll down file and add any usernames you want sudo access:
“new_user    ALL=(ALL) ALL”

Find out more about “sudo” here.

Virtual Box on Windows 10 suddenly throwing new error “VERR_LDR_MISMATCH_NATIVE”.

If you encounter this, deactivate your virus protection and firewall and try to restart.  Seems to work fine after turning virus protection back on again but whitelisting all Virtual Box apps should prevent this from happening in the future.  It’s confirmed that even though I use Avast for this particular server the same issue for McAfee and Norton have been reported.