I was working in a part while I had its drawing open the same time, while I entered "Isolated" mode in SW in order to work more easily in one of its bodies so the same time the hidden bodies dissappeared in the drawing too, but after exit isolated mode the bodies remained hidden in the drawing. Rebuilding the drawing didn't bring them back, I also tried to save and exit the drawing but when I opened it they were hidden still.
I managed to bring them back by selecting each and then Reference Configuration -> Select Bodies -> and then selecting all the bodies in SW part. But I don't know if that is the proper way to do so. In my case I was lucky I'm was in the start of the drawing and I had only few views, but someone has dozens of views, I think that it too much time consuming.