I was working in multi body part environment and used save bodies feature to save some body parts and sub assembly made from those parts. I had no issue in that. But once I changed one part's dimension, the derived sub assembly file got messed up. All derived body parts were updated, even in the derived parts in the sub assembly file but not the connection between those. I did try a lot- rebuilding each parts then assembly even modifying the save bodies feature, but didn't work.