Awakening of Evil

This campaign has stood the test of time. I'm afraid the problem lies somewhere on your end.

I played through it on EWA, and I still remember everything. But I got stuck on a clean 3.1 version. And I remember having the same problem with the surface back then. It somehow got resolved (I don't remember how).
I installed the original game + patch, and that's it (I didn't even bother installing mods) - I can't load onto the surface. The save crashes, and I've made several saves. So, I can get to the surface, even fight, save, but I can't load that save again. I've already tried changing all the settings, and I really don't know what's causing it.
P.S. If it helps to understand, the campaign crashed constantly when reloading a battle, but I accepted it because after the crash, I could load and continue, but in the second chapter, after the labyrinth, it all came to a complete stop (I even deleted old saves, leaving only one, but it still didn't work).