Running the last updated version of the game, I noticed that the Nahant Chapel front entrance and facade texture appears not fully loaded resulting in a very wrong texture rendering. Also in the insides there are two wrong curtains textures located at the second floor of the chapel.
location:
http://vignette1.wikia.nocookie.net/fallout/images/c/c0/FO4_map_Nahant_Chapel.jpg/revision/latest?cb=20151112232524
Regards