'Unexpected error has occurred' - editing account details.

[Pete45]

I'm trying to change my household email address, because the one listed is tied to my old supplier and dies in a few days, but I get an 'Unexpected error has occurred' message. It let me change my mobile number ok, but not email. Is there any way to do this? I logged out and logged back in, in case it thought I was trying to hijack my own account, but the message still appeared. This is on desktop sky.com page, not an app. I have had to switch off email notifications until this is sorted.