So far my first attack on the Skull of Wonders did no damage and there's no indication that an attack even took place.
This seems to be affecting only members of my alliance, and I am currently reaching out to other alliances to see if they are seeing something similar.
Confirmed affected players, so far: Myself (Nasai), TranyBoy, k.Casper
Screenshot below:
http://1drv.ms/1YK8sPo