Putting it into the mildest terms, Alien 3 was an omnishambles. Armed with a trailer and a release date, 20th Century Fox didn’t know what the movie was going to be about, but knew it was going to come out in 1992. A film that had already seen several writers and directors come and go, with just as many concepts making their way through the revolving door, the resulting story came partially from re-writes done by David Fincher himself. In the end, no one would know just how the experience would turn out, as a pretty impressive, yet misleading, teaser promised quite a bit:
Article source: https://www.cinemablend.com/news/2557805/alien-3-director-david-fincher-opens-up-about-what-went-wrong