When uploading maps;
Include the FHM. file, the FHO files associated with your map (After you've exported it) and any sky or weather files that were exported along with it (assuming you have custom sky or weather). Also any music, custom terrains etc, once you've learned to do all of this. Basically anything the Map Maker says its exporting into your Exports folder, is what you need to grab
In most cases of maps causing users to crash, in large mounds, it will be the weather file and how it was made in the sky maker. Suggest to them to remove this and see if the map works without it.
