Incorrect email or password activating online backup subscription

We are using a trail of Acronis Backup and Restore 11.5 in a school. The school uses a proxy (controlled by the local council) to access the Internet so we have entered the proxy details into the program through Options and Machine Options. When we go to activating online backup subscription, the message The specified e-mail or password is incorrect. We can use the same details to log onto the online account fine and can see an outstanding trial waiting to be activate. Please can you advise how we enter details successfully so we can continue the trial.

Also on the proxy screen, when we choose the Test Connection button, we get the following errors:-

Code: 19,267,587(0x01260003)
LineInfo: 0x66612FD7C2237203;

Module: disk_bundle_vs_32266
Message: Cannot connect by using the proxy server.

Code: 19,333,294(0x012700AE)
LineInfo: 0x1AB71F4B090535A2;

Module: disk_bundle_vs_32266
Message: Failed to establish connection with Acronis Online Backup Storage.

Code: 19,333,122(0x01270002)
LineInfo: 0x1AB71F4B090535E3;

Module: disk_bundle_vs_32266
Message: Host adress not found: web-api-tie.acronis.com

Many thanks.