What is the most likely issue if Appoline cannot log in using her provided username and password?

If Appoline cannot log in using her provided username and password, the situation where the account was created with no initial password stands out as a likely issue. When an account is set up without an assigned password, the user would not be able to authenticate themselves when attempting to log in. The absence of a password essentially locks the user out of their own account until it is properly configured.

In contrast, other scenarios, such as incorrectly spelling the username or having an expired password, would also lead to login failures, but they stem from errors or conditions already present in the account setup or usage. If the system were down for maintenance, the impact would be broader, affecting multiple users, rather than just Appoline. The key issue highlighted in this context is that without any password, successful login is impossible regardless of the correctness of the username.