Feral Heart

Problems with the height map such as its size and whether it's in grayscale or not, would cause problems in Map Maker and would crash the game as soon as you entered the height map's name into Map Maker. So I'm willing to bet that you have double particles that are created each time you close out your game due to the map or something in it, that's happened to me before too. No big deal, just delete any particle files ending in _0, _1, etc like Kynvuu said and it'll fix your crashing problem.

It could be too that you have objects the game no longer recognizes and it crashes, that is if you've downloaded any new objects to use, but if you're using only the defaults then something might either be misplaced or missing, as Kynvuu had mentioned, try exporting the objects you used into a custom group and see if that helps. I've got a nifty tutorial for replacing or changing objects in a map without having to redo everything, so I could post the link to it if you need it.

You could always try reinstalling as well in case nothing above helps.

If it keeps crashing upon your return to it before you even get into the map maker then it definitely sounds to me like this problem here:

Quote from: Kynvuu on July 13, 2016, 02:48:02 pm

-Make sure there are no duplicate files in your exports folder

Be sure to check that well. Particles etc.

It's not anything in her game that is the problem. I am having the EXACT same issue as her. The exporting system must have gotten destroyed in the new update and it needs to be fixed.
To explain in a bit more detail than Minti did...

I will be making my map, la da dda da dee~ and then I will want to export a "beta" version of the map. I exported it and sent it to my friends. Since I wanted to go into the map with them, I closed my feral heart, (like you're supposed to when you download things)  but when I try to go back in the game won't load at all... like it's corrupted. I've resorted to having to make a copy of the ENTIRE FERAL HEART FOLDER before I export my map or I will lose EVERYTHING. This is consistant. I've tried redownloading the game, I have scanned files for hours, it is something technical with the game.

Not only this, but when I create objects in the map maker and I try to put them in my map, once I export it they cannot be seen. This includes importing meshes from other people. If the people have an object file to group their objects already they work; but if I have to load the mesh and save it myself, it won't work. For example, I tried loading in an individual log mesh. It worked, I put it in my map and it was perfect. But, once I export the map, it's gone. Another example, I wanted to make a group of reeds so I didn't have to place every reed individually and I had the same problem.

These really need to be fixed in the next update or I'm not going to be able to work on my map properly, along with every other map maker.