About 10 minutes ago i decided to make my first trip into the volcano and grab whatever resources i can. The first time i went in, i spent only about 2-3 minutes, picked up a coffee plant, some volcanic turf and dug up a few magma piles and then the game lagged a bit and closed without any error message (it also didn't freeze, it closed smoothly). When i opened the game up again, i was able to spend a while longer in the volcanoes before the same thing happened again. This time i grabbed some coffee plants again, dug up some magma piles, killed a few dragoons, got one cactus plant and then the game closed by itself. Both times without any warning except for a very brief lag before it closes. My internet is working fine so that shouldn't be the issue.
Kind of frustrating with this being my first volcano adventure >_<
Go into the volcano, dig up some resources or spend x amount of time in the volcano.