Since updating to Win 11 24H2, I have been encountering 2 issues. One is the virtual memory error as outlined by others. The other issue is that when it does work, it forces multiplayer even if I select single player. Same issue in both SMAC and SMAX, and only since updating Windows.

Also just updated to 24H2... Haven't had the virtual memory error, but it forces multiplayer when I am playing single-player.
Original Alpha Centauri works fine though.

this is how i setup and order it, i only play alien crossfire, not regular alpha centauri. and i got the planetary pack on steam not gog but i dont think its any different.

i installed in this order
game from steam
smacp4e patch
smacxpv2 patch
smac_win2000_xp_compatable_update_v1_03f
unofficial SMACX Sound Effects fix-2-1-0
Yitzi 3.5 patch (alphax needed renamed to Alphax, note capital
yitzi 3.5d executable
pracx.v1.11.exe

enabled PRACX in "alpha centauri.ini' disabled forced old voxel algorithm, set screen width to 1024. otherwise movies were broken.

[PREFERENCES]
ForceOldVoxelAlgorithm=0

[PRACX]
Disabled=1
ScreenWidth=1024

When are we going to get a fix? It's on GOG's preservation program...