I have the 17 November 2024 update for Sid Meier's Alpha Centauri Planetary Pack installed, and was running Alien Crossfire with my usual preferences as normal through 21 November 2024; however, when I tried playing SMACX this evening (22 November), I had a couple of major glitches immediately after my faction's landing on Planet:
1) I got a pop-up message that "sea levels are rising dramatically!" (This message repeated on each succeeding turn.)
2) I then got a message that all factions could now work on the Ascent to Transcendence (something which ought not happen until the very late game).
3) Although I saw our faction landing, our faction's initial colony did NOT appear on the map, and no units appeared on screen, so I couldn't build anything in my initial colony, and couldn't explore or build new colonies.
I had been playing Alien Crossfire with a custom mix of factions (the 5 new human factions, plus my 2 favorites from the original game), so I tried playing Alien Crossfire with the original Alpha Centauri factions, and encountered the same problems.
I would note that, if I play the original Alpha Centauri post-update, these problems do NOT arise. However, I prefer Alien Crossfire -- IF I can get it running glitch-free again!
ETA: I would also note that the sound is a bit "crackly" when the mouse is clicked in the original Alpha Centauri post-update. The crackly sound, however, though annoying, does not make the game unplayable the way this new "Ascent to Transcendence at game start"does.

I get none of these problems when playing Alien Crossfire on Linux (using the Loki native engine), so at least the game data is probably in a good state, including audio files.

This at least gives us good reason to think the problem is related to the game binaries or the shipped libraries. I still have access to the previous GOG build, so I can run a comparison between the content of the current installer and the previous one if you wish.

I won’t be able to help further than that, as I don’t have access to Windows.

Thanks! That would be useful information, at least. I remember having to troubleshoot the previous build with the help of GOG tech support, and had to install a couple of patches from outside GOG to get Alpha Centauri or Alien Crossfire to run on my Windows 11 computer.

Using setup_sid_meiers_alpha_centauri_2.0.2.23.exe as a baseline, and as the updated version setup_sid_meiers_alpha_centauri_planetary_pack_1.1_pracx_ddraw_(77244).exe:
- The shipped *.tmp files have been dropped, they probably should never have been included in the first place;
- Some GOG-specific *.dll libraries have been dropped (gameuxinstallhelper.dll, goggame.dll and goggame_add.dll), probably related to the updates of the build system over the years;
- "alpha centauri.ini" has been modified (I can check the details if you wish);
- The following files have been added:

Along with the rather obvious "terran_widescreen" PracX is a program for facilitating modern resolution changes (for widescreen), which is the kind of thing I heard that GOG included. I have no idea why it would cause your bugs, and may very well not be related.

If you want to try uninstalling prac x, it can be downloaded from third party (and reinstalled with the whole game I suppose). Maybe a reinstall of the game would fix your problem.

Although I believe it was updated a few years ago, PracX itself dates back to at least 2014, when I made the unofficial patches thread.

Perhaps I should uninstall and reinstall the game? If a fresh download of the game from GOG would already have the update included, maybe it would run better than it currently does, with the update applied to a heavily-patched pre-update install of the SMAC Planetary Pack.
ETA: I tried the "Verify/Repair" option under "Manage Installation", and after that I was able to open Alien Crossfire with a gorgeous full-screen (4x3 fullscreen rather than widescreen, but close enough) intro movie. I then opened a new game (rather than a Quick Start, as I had been playing the original Alpha Centauri most recently, and wanted to pick the factions I wished to play with), got things set up the way I've normally played, and my first colony displayed normally upon landing -- but then I got a prompt for hot seat/email multiplayer (which I had NOT selected during setup), and the game crashed right after I got out of that multiplayer popup. Reattempted starting the game, being careful to NOT select multiplayer during setup (in case I had inadvertently clicked it during setup the first time), and the same thing happened. Clicked the second "SMAC PRACX" link in "Additional Executables", and got the small-screen intro movie; started a new game (instead of a Quick Start) again -- but got the "sea levels rising dramatically; all factions can now buld Ascent to Transcendance" message again. Maybe uninstalling and reinstalling will have to be the way to go. :(
ETA2: Tried clicking the first SMAC PRACX link in "Additional Executables," and got a normally-running game of the original SMAC running (w/small-screen intro movie). Will need to check the main "Play" button from the GOG Galaxy page for this game; I'm predicting that I'd also get a normally-running game of SMAC that way, but don't yet know if the intro movie will be small-screen or large screen. (Less eyestrain with full-screen cutscenes, but I can live with small-screen cutscenes in exchange for a playable game.)

i don't understand all of what you are trying to say. But PracX itself has an uninstaller, if you believe that a resolution program is somehow related to your problem.

The uninstaller is titled PRACX.v1.11.Uninstaller. You can find it in your Alpha Centaur folder by pressing P. I am not a GoG staff myself, but this is not a program they are trying to shove down your throat. I believe it was made by fans of the game.

If it had been the cause, I suspect it would have come up some time since 2014.

Prac X itself has a separate executable. The prac x versions are under terran_PRACX and terranx_PRACX for the expansion.

The game doesn't even open with it by default.

I don't think it's a resolution problem. It's a bug in Alien Crossfire post-update, which gives me a pair of very late-game pop-up messages ("sea levels are rising dramatically" and "all factions may now build the Ascent to Transcendence") on the very first turn, and also doesn't show my faction's initial settlement on the map after landing, nor any of my starting units. I don't know what's causing the bug, and it appears to be specific to Alien Crossfire, as it does not occur in the original Alpha Centauri post-update.

I don't know what that would be. The only files you have listed appear to be related to prac-x, which has a seperate executable from the original terran x executable. I don't know if any of the DLLs you have mentioned even exist outside of prac-x, you could potentially delete them and still run the game.

@vv221 listed files included in the update. I did not list any files myself, since I do not know which files caused the bug I have experienced when attempting to run Alien Crossfire post-update. Also, it might not be possible to roll back my installation to what it was pre-update, as one of the first things I did when attempting to troubleshoot the bug was to uninstall the SMAC Planetary Pack, and re-install it, which installed the current updated version.

If GOG support can’t help you get your hands on the previous version of the game (please try that first), you can find my e-mail address by following some links from this post.

Get in touch with me using that address and I should be able to help you rolling back your game to the version that was working for you: I saw from your profile that you own a legit copy of Alpha Centauri from GOG, so I would have no problem sending you a copy of my backup for this installer (the one before the latest update).

I contacted GOG game support a couple of days ago; waiting to hear back from them. I'll let you know if I need further help. Thanks for the offer!

GOG Support finally responded (after 12 days) with instructions for rolling back the game to a previous version. Since I had previously uninstalled my heavily-patched GOG install of the Planetary Pack as a first troubleshooting step, rolling back to a previous version just took me to the Alpha Centauri and Alien Crossfire versions with the large-format intro movie cutscene display, and Alien Crossfire still has an unplayable bug pop-up on the first turn (this time a "hotseat multiplayer next turn" prompt, when I've NEVER played SMAC/SMACX with multiple non-AI players. Sent a follow-up message to GOG Support reporting on this.
Apparently I also own the Steam install of Sid Meier's Alpha Centauri Planetary Pack, which doesn't run on my Windows 11 computer (but DOES run fine on my husband's Windows 11 computer -- go figure!). I checked the Steam discussions on the Planetary Pack, and it appears that quite a few people who own the Steam install of this game have experienced similar problems. Some are blaming the current issues on the most recent Windows 11 update. I would love to see confirmation (or debunking) of that theory from someone official at GOG or Steam.

I am having the same problem play the game. I have tried every patch and despite owning the gog version I cannot get the game to run now after windows 24h2. I deeply hope they solve this problem.