This rather grim bug occurs for me (iPhone 6s) On the Seige Coast, the area right after the bandit siege gun right of the town.
The most common version whenever of this bug is when the game transitions from the victory screen to the world map, so after XP and loot have been provided, I press next, the screen goes black and about a second after it crashes.
I believe, though it’s harder to reproduce, I’ve also had a similar version of this happen where it crashes as it gives me the loot, again from enemies in this area.
Sometimes the game crashes right when I engage an enemy, so instead of having the Fight! splash screen thing, it just crashes.
From what I can tell, this isn’t an issue elsewhere in the game world, so in my rather limited knowledge of how a game works under-the-hood, the issue is probably in the data for the enemies that spawn in that region, specifically with the loot they drop.
This only became a problem after version 1.0.15, which was launched ~2 weeks ago, so I’m guessing it mucked something up.
A real shame too 'cause I was having a blast with the game. Hope something can fix this.