What's the absolute worst ending(s) to a movie you've ever seen or even heard of?

Two that immediately come to mind for me are:

The Devil Inside literally

I'm dead serious. Whoever thought THAT was a good idea during pre-production needs to be slapped, or better yet, fired.

Oh and Catacombs, a straight-to-video B-horror movie has one of the worst "twist" endings I've ever seen. It barely even qualifies as an ending. Basically,

Really, that's how it ends. As if it weren't bad enough that the movie was already dogshit leading up to that point, there's a reason why it was straight-to-video.

I'm having trouble deciding which is worse. They're both bottom-of-the-barrel in their own stupid way.

There a couple things that qualify, but The New World with Colin Farrel is always a go-to answer for questions like this.

This movie sucks through and through and the ending doesn’t help things. It’s boring beyond belief, and even though it had a regular length it feels like you’ve been watching this thing for four hours. Nothing really happens, and it moves unbelievably slow. Until like fifteen minutes before the end. Then all of a sudden decades fly by; Colin Farrel goes back to England then goes back to the New World then gets a kid which grows up discovers a cure for cancer and builds a spaceship to go to Mars and then he dies which we really need to feel very sad about. Okay obviously he doesn’t go to Mars but you get the idea.

I actually watched this in the cinema, and apparently my opinion of it was much like that of the rest of the audience. When it was over, someone behind me blurted out “Wat een kutfilm”. I’ll let you guess what that means. I should’ve gone to Ice Age instead in the next room.

Dunno about worst ever, but I hate completely contrived twist endings that do absolutely nothing to earn their surprise; no setup, no foreshadowing, and God forbid it make any actual logical sense. Shyamalan is of course famous for this, but another movie I saw that comes to mind is The Tourist. Haven't seen it but I heard Now You See Me falls in this boat, too.

I've only seen it once and it was a fair while ago, but I seem to remember The Happening having a bit of a crappy ending.

And whilst I do enjoy the film for the nostalgia and the so bad it's good factor, I recognize that Jaws: The Revenge has a terrible ending (and is generally terrible throughout).

Independance Day 2

I don't know exactly which have the worst movie endings, but I am just not a fan of movies where the main protagonist dies in the end.

Interstellar.

The movie is pretty darn good until we get to the bookshelf.

I don't think it's the worst ever, but the ending of Breathless (Jean-Luc Godard) is the first one that comes to mind and definitely one of the worst that I've watched recently - in spite of the movie not being bad.

[Edit] Many would disagree with me, by the way, but I just find it ridiculous and pretentious.

Interstellar. Wouldnt say "the worst ever"; but certainly one that disappointed me a lot.
First 2 acts of the film were fantastic, third act takes a deep dive to stupidity.

Curse of the Golden Flower; felt like they just had no idea how to conclude the story's arc and so it just ended.

Godzilla vs Kong 1962 version; the ending is a total cop-out, leaving it lazily ambiguous but hinting towards an illogical Kong win just to placate American audiences. Thank fuck the 2021 version corrects this.

Planet of the Apes 2001 version; the whole film is bad but the ending is just so silly and nonsensical.

I'm sure I could name tons more but for some reason I am having a mental blank atm.