Welcome to our Community and thanks for your first post to our Forums (we have merged your duplicated post with this one to avoid further duplication and any confusion). I was sorry to understand that you're having some issues registering for your online MyVirginMedia account at the moment.
I have located your account from your forum information and can see that as yet, one has not been registered and no attempts yet been made.
Can you advise how you are trying to register? Is this via our website or via the MyVirginMedia app? When does this issue occur - is it after you have popped in your Account number and pressed register or after?
Sometimes this error can appear if you have left spaces at the end or beginning of the box. The account number must also be 9 digits ling. Any less and it won't work. If your account number is less, please add zeros to the start of the number to make it 9 digits long.
Pop back if you're still having issues and answer the questions and we'll go from there.