A situation which, contrary to expectation, turned out to be uninteresting, unimportant or unexciting; an anticlimax
non-event non-events in AM, also use nonevent If you say that something was a non-event, you mean that it was disappointing or dull, especially when this was not what you had expected. Unfortunately, the entire evening was a total non-event. = anticlimax. an event that is disappointing because it is much less interesting, exciting, or important than you expected