I just tested on 3 different servers. One live server in the US, one live server in the EU and a testing server in the office. All three could upgrade correctly, so it doesn't look like a problem on our server side.
If you are getting the exact error message as the original poster, you really have to talk to your host. Ask them to open connections to ports 80 and 443 to AkeebaBackup.com (IP address 18.104.22.168). If you had done that a few months ago, you'll have to do that again. About a month ago we installed an SSL certificate on the server. In order to do that we had to be assigned a dedicated IP address, which means that our domain (akeebabackup.com) remained the same, but the IP address it resolves to has changed. Since your host's firewall filters traffic based on IP addresses, you have to ask them to open connections to ports 80 and 443 (standard and SSL-encrypted HTTP traffic) to our new IP address.
This is exactly what I suggested in my June 24th reply
right above your first post. Have you tried that?
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!