The most likely reason is that the case status is awaiting to be updated. From what I know the message usually shows up if there is a status update coming near. It may not be a site down maintenance message as that is usually indicated on the USCIS website or when it happens it occurs during the weekend.
Is the USCIS website just down or is something wrong????
in K-1 Fiance(e) Visa Case Filing and Progress Reports
Posted
The most likely reason is that the case status is awaiting to be updated. From what I know the message usually shows up if there is a status update coming near. It may not be a site down maintenance message as that is usually indicated on the USCIS website or when it happens it occurs during the weekend.