I'm not quite sure. It's been a couple years since I've played that game.
What crashes SC:
1. High Index colors (Player color) like 145 and 255. Stick with colors 0-17
2. Maps with illegal dimensions
3. Units placed off the edge of the map (buildings)
4. Placing sprites off the edge of the map.
5. Many sprites crash the game.
6. Illegal units may crash the game such as an Independant Command Center.
7. 2x speed tends to crash the map.
8. Showing the portrait for a unit that does not exist. (including mission breifing)
9. Many units crash the game when disabled.
10. Placing a tile index that doesn't exist.