Just saw a show on Netflix about the making of Ghostbusters, part of a series, there was an episode about Diehard as well. When they started shooting Ghostbusters they didn’t have the rights to the name yet, there had been an earlier really low budget movie called Ghostbusters.
So every shot that mentioned Ghostbusters they had to do an alternate take using “Ghostbreakers”, the backup name.
The exec from Columbia who greenlit the movie originally got fired halfway through and then hired by Universal, who originally owned the name, so he told them to sell the rights to Columbia and the rest is history.
Worth a watch if you have an hour.