Cannot sign into my EXISTING Yahoo mail account - says ou can no longer create a new Yahoo Mail acco

[daveyboy22]

I have an EXISTING Yahoo account but, since yeaterday, when I try and login a message says 

Sorry

You can no longer create a new Yahoo Mail account via Sky.

The chat and help messages do not resolve this issue.

[Mark39]

How are you trying to log in? Can you log in here: www.sky.com/signin/email ?