So, I've completed all five of the characters scenarios, but there's a problem. The game takes me to the screen showing the AM Monolith, and AM says something like: "You are the last player in our little game. Please, do not fail where the others have failed." After that, I am just stuck in the AM Monolith screen where you would normally choose a character scenario. I can move my cursor, but there is nothing to click on. Somebody, please help me! I would like to play the ending scenario. Here is a photo of my screen after I finish all of the character scenarios:

I think that screen is supposed to play when you've done 4 out of the 5 characters and the screen is supposed to show a character to click on. So this seems (to me) to be a bug.

Can you provide a saved game near the screen when this happens (ideally not from this screen itself, but a bit earlier)?

Since the game is powered by ScummVM on GOG, but the bundled ScummVM version is quite old (2.0 from 2017), could you test with a more recent ScummVM version (currently we're at 2.8.1).

I loaded from an earlier save using ScummVM 2.8.1, and I finished the fifth scenario as normal. The problem still persists. I am going to upload a copy of the save file. It is Ted's scenario, and all you have to do to finish the scenario is break the mirror in the ritual circle. How do I go about sending you the save file?

You could upload the save game to a Google Drive location and post the shared url here.

Alternatively you could open a ticket on ScummVM's bug tracker (you need to have or create a Github account for that), describe the issue there and attach the saved game.
https://bugs.scummvm.org
https://docs.scummvm.org/en/latest/help/report_bugs.html

https://drive.google.com/file/d/1fsqPgdAmEpelYoZiO9k1UgjuckEDAMoQ/view?usp=sharing
Here, this should be the correct save file.

Unfortunately, this does not seem to be the correct save file. It's called "Save 5" and it's from Elen's part somewhat early in the game.

Sorry for the mix-up; the file names are a bit off.
This file is definitely the right one: https://drive.google.com/file/d/1B12hWTxuMUCjUqWccDclIczH8hAOIWSm/view?usp=sharing

Could you allow access to the file to anyone with the link?

Yes, sorry about that! It should be open now.

Thank you.

I can confirm that I'm seeing the same bug on my side (using ScummVM 2.8.1 and also a development build of 2.9.0).

The issue seems to be that a variable that keeps track of the characters that have completed their chapters did not get decreased after some character's chapter end.

I was able to play through the game and up to the start of the final segment without encountering this bug, starting from your earlier save ("Save 5") which was at Ellen's chapter, using ScummVM's 2.9.0 development build. So I went through Ellen, Benny, Nimdok and Ted, and I've encountered some glitches (especially during Ben's chapter) but still not this bug.

Unfortunately, I cannot say what would cause this particular bug off-hand and I'm not very familiar with this particular game engine implementation for ScummVM. Do you recall any weird issues at the end of the chapters for these characters on your end, meaning Ellen, Ben and Nimdok?

It might be possible to fix the problematic variable in the saved game you provided (not sure yet how easy that would be), but I still can't tell if anything else got "corrupted" as well at the point when the bug originated.

Again, I'd recommend this to be posted as a bug on the official bug tracker so that maybe a developer of this specific engine would offer better insight and solution.

Here's the save file fixed with a hack -- I edited the file to change the bad value of the variable tracking the completed scenarios.
https://drive.google.com/file/d/1gHrqijzrHhIPaIShoul-STF3LgcyJVXZ/view?usp=drive_link

In technical details, the value change was a "02" changed to "01" at the 0xA0B8 address of the (uncompressed) saved file. Note, this address is not the same across saved game files, so it won't work for other saved games).

It seems to work, ie. it proceeds to the final segment. I cannot tell if the saved game had other corruption though.

It would be good if we could figure out exactly what went wrong, and when (which of the 3 possible scenarios did not end properly? Elen's, Ben's or Nimdok's?) so we can fix it, if possible, on ScummVM side. I tend to suspend Ben or Nimdok, because Ben's is in general a particularly glitchy scenario and Nimdok in your playthrough seems to have failed (died?). But there's not enough info to tell.

I have opened a bug ticket on the ScummVM bug tracker here:
https://bugs.scummvm.org/ticket/15214

I've put any info and auxiliary files that I could think of as helpful. Feel free to add more details or clarifications.

Thanks for the help! All of the scenarios seemed to be normal, and I didn't encounter any bugs, besides the one we're talking about now. Nimdok did not die in my scenario, but he did tell the Golem to kill the Lost Tribe.

Actually I think that helps a lot.

I believe I've found where the bug originates, and it's in Nimdok's scenario.
I guess this is spoiler territory for anyone not wishing to find out about critical actions that are accounted by the game for this scenario.

So spoiler:
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As far as I can tell, the game considers at least two actions as major during this scenario, and tracks them with global flags (this is separate than the "score" for Nimdok where I think more actions count). One is getting the mirror and looking at it, and the other is how you deal with the final choice about the lost tribe (when you have the Golem with you).
If you look at the mirror, then no matter what you choose in the final choice (kill the tribe or transfer control of Gollem to tribe) the game will consider the scenario finished.

However, if you don't take the mirror (or if you don't look at it), then the final choice can only be to destroy the lost tribe (or transfer Gollem's control to Mengele who will destroy the lost tribe, if you didn't have him look at the mirror). In this case the game will consider the scenario unfinished, and at the same time finished. Nimdok won't appear in the character selection screen, but AM's "epilogue" for the scenario suggests that Nimdok has to restart his scenario. Also, while only Ted is shown (if he is the last character), AM will not be using his special speech for the "final" player.

I will update the ticket on the bug tracker with this info.