Only thing I can think of is maybe your ISP decided to block it or your IP was accidentally blocked. Since you tried all those things and it still doesn't work it kinda seems like it's IP related.
The adblock error message you get doesn't necessarily have to be because of adblock and could just be a standard error message you get when the specific reason can't be identified.

If you have a second computer available (with a different public IP) you could try checking there, or if you're on DHCP try releasing your IP and fetching a new one maybe?