I found following messages regularly in my .rpts, on hosted games and also dedicated server.

EntityAI SubSkeleton index was not initialized properly (repeated 140x in the last 60sec)
name: Land_Shop_City_03_F, shape: a3\structures_f_exp\commercial\shop_city_03\shop_city_03_f.p3d, index: -1, matrices: 4

Its always for the same object type.