IDF-12B

I am trying to register  for a Virgin Media O2 ID using an active  ntlworld email address but I am receiving the following message;

This Virgin Media email address isn’t valid  You've tried to sign up with an invalid Virgin Media email address. Check you’ve entered the address correctly and try again. Alternatively, sign up with a different email address.

or a message with code   IDF-12B

I am able to send and receive emails on all my devices.  I need to be able to set up a Virgin Media O2 ID in order to enable me to access and change the password.

I have 2 other ntlworld emails and have successfully set up Virgin Media O2 ID's for them.  I have followed all the "Help" and am not using a  vpn.

Your help will be very much appreciated.