I got it working now. It seems the romfs-file was corrupted of some sort during dumping. Check the size of your romfs file Nat1Gamer. It should be around 1,8 GB. Mine (the one I had when the game crashed was 1,1 MB. Redid the process, and now it works like a charm! Amazing game, but god damn, the difficulty level is harsh!!!
Hope you get it to work