All questions regarding mapmaking for Heroes of Might and Magic 3: The Shadow of Death.

Lux in tenebris, the map is alive and full of energy, no problems. Just in case, I saved it again, try it. Regarding the issue, try disabling one core on your dual-core processor. I also recommend downloading a program to optimize the work of multi-core processors. I just don't remember the name, it's something like CPU Control.