Noticed today (July 16, 2022).
In the first paragraph of the entry, it states that the Allagan Empire was founded in the "aftermath of the Third Umbral Calamity...".
Later, the end of the second to last paragraph, it states "The Crystal Tower's collapse triggered a series of earthquakes which shook the entire realm, bringing about the Third Umbral Calamity...".
Obviously, the Third Umbral Calamity cannot be both at the start and end of the Allagan empire, so one of these Calamities is misnamed (should start with the Second or end with the Fourth). Based on the Encyclopedia Eorzea, the empire should end with the Fourth Umbral Calamity.