Multiple CGI Mistakes
Despite wanting to use as many practical effects as possible, Cameron obviously had to use some CGI for some of the more complex things in the movie. This created a whole array of problems, from shadows that don’t look realistic to vanishing objects that appear and disappear from the ship’s deck, and pipes that change their shape through the movie.
This is the risk of using CGI in a film (especially during the ’90s), but it’s still not great that those weren’t left on the editing room’s floor.