Wrong hotel code, username or password
One sentence for all three, and the one people actually get wrong is the hotel code.
The sign-in screen says Wrong hotel code, username or password — the same sentence whether the hotel code is unknown, the username does not exist, or the password is wrong. It has to: a screen that says "that hotel is not a customer" answers a question strangers should not be able to ask.

In practice, in order of likelihood:
- The username typed as an email. Since September the username is short —
FOM1,HK2— and it is not the email address. - The hotel code. It is the hotel's letters (
ASARSJ). An administrator of a group types the group's code, not a hotel's. - The password. Passwords are case-sensitive; the eye in the box shows what was typed.
"Locked until … after too many attempts" follows five wrong tries in a row and lasts fifteen minutes. An administrator setting a new password clears it at once.
A login with no username yet cannot sign in with a username at all. The administrator opens Team & access and uses Login name on that person's row; the list says *No username yet* against everybody who still needs one.
An administrator on your side fixes all of these from Team & access. If the only administrator is locked out, telephone us — and afterwards, make a second one.