ESO support wrote:"We believe Sheogorath had a hand in causing this trickery as the game needs to load, refresh and phase itself with the player again. This issue allows the player to be attacked and appear as though they are existing in a world where they are non existent! This veil of trickery does not normally last longer than two minutes. Sheogorath is indeed a Mad man, however me and the mages have found a way to combat this new source of trickery."
"May Sithis return your techincal difficulties to the void"