I have a laptop running windows 11.
Windows update forced me to install Version 24H2.
I can run SMAC but when it writes to disc (autosave) it crashes with FATAL ERROR message and tells me to increase my Virtual memory to 128MB. Current configuration is 24576MB.
Terranx.exe is running in XP compatability mode.
Everything worked before the update.
Any patches that will fix this appreciated.

The original SMAC works on Windows 11 version 24H2.
The Crossfire expansion is the game that crashes.

I'm having the exact same error.

I am having the same issue

Toggle Directdraw in the ini. If that doesn't work, maybe try WSL, installing Gamescope, and then running it via Wine in Gamescope.

I enabled direct draw (in Alpha Centauri.ini I set: DirectDraw=1)

Same error.
Full error text is:

FATAL ERROR
Windows has run out of virtual memory; the game will exit.
Recommendations: defragment your hard drive; use Control Panel (System/Performance/Virtual Memory) to increase your virtual memory to at least 128MB

For the record, my virtual memory is in the gigabytes and managed by windows, so its size is dynamic.

Ah, it's done a good ole overflow.

Dunno how to suss that out in Windows, frankly my other insane solution might work.

Edit: A new build has appeared. Maybe give that a try.

Tried with the latest patch, upgrading using gog galaxy.

The game crashes at the same moment as before, when it tries to create the first base but now without showing any error message.

This is with the standard terranx.exe launcher.

With the PRACX launcher (terranx_PRACX.exe) now included in the gog version it still displays the virtual memory error.

Not sure you are going to be happy with that suggestion, but at least it is guaranteed to work:
1. Install Debian GNU/Linux;
2. Generate native .deb packages for Alpha Centauri using ./play.it;
3. Install the generated .deb packages using apt, the default packages manager on Debian;
4. Start the game from the new menu entry added by the installation of these packages.

I'm also having the same problem with the latest patch on Alien Crossfire.