One of those statement indicates you are setting up a new account. The other says you have your account contiguered and it is not working. Running the new account wizard is not a solution for a non working account. Have you looked at the yahoo site to see if you are included in their current outage? https://au.help.yahoo.com/kb/SLN36847.html?impressions=true That article implies you need to remove the Oauth:// entries in Thunderbird password manager for the account. https://support.mozilla.org/en-US/kb/password-manager-remember-delete-change-tb I am left wondering who hacked their oauth database.