I'm not an expert on map making, but from my experience seeing this kind of thing happen here on the forums, I've noticed it may be caused by a few things.
- As Notorious has already covered (I was typing this before they replied), you may have duplicate particles in your particles folder.
Head into your FH > Media > Particles/Objects and make sure you don't have any files with _1 etc added to them.
Duplicate particles and others can cause the game to crash.
- Make sure that your map is 513x513. Also make sure that your heightmap is in greyscale.
- Objects can cause your game to crash as well if you have a bunch of them. It all depends on what your PC can handle, though.
- A file may be corrupted, and there's a possibility that you'll have to check them all to find this out, if none of the issues above is what is causing your game to crash.
- You may have to reinstall if none of these issues is what's the matter, just save all of your map files in another folder on your PC.
I hope some of these are helpful with the issue that you're experiencing, let us know if not! <3
This problem happens after I finish one of the maps and export it to further upload it on the internet afterwards (mediafire), other than that, I know how to create and make maps, I'm an old member joining in with another account because I completely forgot all of my previous information of my older account (haven't been on FH for years).
About the files having _1 or _2, the only ones I find are in the particles folder: water_0.particle water_1.particle
But since I haven't installed anything into the game itself after exporting the map (by installing anything into the game, I mean like different meshes, etc.).