Accessing https:// to an IP should give that error.
But it shows that you do have access to the IP.
I still don't see the IP of the client PC; but the PC and the server seem to be on the same LAN.
So I'm confused on why it presents that error when you added the the entry in the hosts file.
Let me crosscheck the facts...
[and take nothing for granted]
What is the IP on the client PC?
What IP is shown by the client PC when you ping the server by its' full name [FQDN]?