When trying to update the software with "Check For Program Updates..." embedded in the software I get "Unable to resolve host name" message.
I have tried disabling Comodo Firewall and Antivirus with no effect.
It's just doing a DNS lookup, which is working OK for us here at least.
If the issue is coming from your local network or ISP then it's not something we can do much about on our side.
Make sure nothing is blocking Opus in any way, and maybe try again in a few hours in case it is an intermittent problem with the ISP.
Or try using Google's public DNS servers (8.8.8.8 and 8.8.4.4).