The fact that map view itself is 404ing, but the other event views are functioning as expected, is certainly strange.
Taking an event you have running on March 27 @ 10:30 pm – 5:00 am as an example though the map does appear to display as expected.
So dealing with the first issue with map view itself initially, I can’t help but wonder if there is a conflict somewhere along the line. I see you did already try deactivating all other plugins/switching to a default theme – can I ask if that uncovered any conflicts? Can you also repeat those steps and, once our event plugins are the only ones still active and you have a default theme in place, visit the Permalink Settings page (you don’t need to change anything, just visiting this should refresh WordPress’s list of rewrite rules) then see if that resolves the 404 issue?
Thanks!