This error message is perfect because it does *everything* wrong.
An error message should:
- Explain what happened
- Explain why it happened
- Enable you to fix the problem.
This message implies that the user had signed in with a mobile (cellphone) number. I hadn’t. Even if I had, it’s unclear why this should be a problem. The solution offered is to “Logout”.
An organisation should use consistent language. Here, we have “sign in” and “logout” – a clear indication that there is internal dysfunction and disconnection.
A key component of a trusted website is good grammar. Here we have “a Optus Mobile number” instead of “an Optus Mobile number” and “Member Services” treated as singular (“Member Services is only…”). Probably the rationale for the latter is that “Member Services” is an entity of some sort, but it’s clearly a case of the organisation speaking its language rather than that of the user.
The message also has two conflicted personas. The first is the one that opens with “Hi” – it’s the voice that Optus uses in its advertising, and even in its installation guides. When everything is fine, that tone can be acceptable, but when things go pear-shaped, it quickly sounds insincere, flippant or blatantly uncaring.
The internal focus is also apparent in the sentence: “If you are attempting to Sign In with your Optus Internet username…” which assumes that the user knows what an Optus Internet username is. I can only speak from my own experience, and I don’t know what it is (nor do I even have an Optus mobile phone number, so that part of the message is doubly confusing).
In fact, the whole message is so bizarre that the fact that the referenced “Logout” button “in the top right of your screen” does not in fact exist seems only incidental, a mere peccadillo amidst a multitude of other sins.