Your friend could try deleting the map and all its contents from her Exports folder and re-downloading the map again.
The .fhm file is the actual map file containing all the objects, weather, sky, terrains. Deleting it will remove all those, hence stopping the game from crashing. But really it may be an error with the .fho, .fhs or .fhw.
It may or may not have something to do with the .fhm but maybe the other files. Try my first suggestion and see if it has any affect at all c: