The OVA sucks. Don't use it. It was rushed to market and is HIGHLY unpredictable. It fails to install, fails to join the domain, falls off the domain, throws MySQL errors, fails to initially configure properly, and, apparently, the staff at ESET doesn't really know the product either.
This OVA should be considered alpha/beta software. Bite the bullet and install the server on a Windows Server. You will thank me later.