Five MONTHS? Look at the date of the first message of this thread... Five YEARS, so far.I'm kind surprized this is still an issue after 5 months....
The blocking of the key domain isn't tied just to MakeMKV, but it is tied to where the author is located. This forum gets away with being able to be resolved in DNS because it is separate. Originally, the keys were pulled from the makemkv.com domain, until they started to make this domain "go away" as a "piracy-supporting domain". The author separated the domain to keep the forum alive.
Crabdance and fairuse have endeavored to support "questionable" places for years, but a number of DNS-resolution companies have been complying with legal dictates to isolate those places. If your DNS provider is one of them, you cannot resolve ANY host in *.crabdance.com or *.fairuse.org, as well as dozens (hundreds?) of others. That's why you need to either (a) use a DNS provider that isn't blocking them, or (b) bypass DNS look-up using an entry in your hosts file. Sometimes, you need to use a VPN connection to bypass some providers, WHEN YOU NEED TO DO A LOOKUP.
That last part is the key - you do not have to enable a connection to the key server to run MakeMKV, unless you need a key for a new disk. If you don't rip 4K disks, who cares?
Right now, both hkdata.crabdance.com and hkdata.fairuse.org are off-line, but the statement posted in this message does still work. The host is there, but the DNS entry isn't.