some ntlworld.com email accounts failing to be added (locked duplicate)

I have successfully added five ntlworld.com email accounts in Thunderbird but my two personal ones keep coming up with Authentication error. Each time the screen shows the details of the account found automatically so the information is coming from somewhere. Advice I gratefully received was to Disable the account hub in Settings / General, then add the account from New Account, and use an application specific password assigned via your email provider. Virginmedia no longer seems to acknowledge ntlworld accounts but says they are talktalk. However, talktalk says they do not hold the accounts. I do not understand how I can disable the account hub in Settings when it has not loaded. I cannot understand why two of the accounts do not load.