Reproduction steps oh iPad (newest gen), version 2.4:
1. Create save portal
2. Enter dungeon
3. Fight monster until you find treasure, e.g. Sword +1
4. After fight select any player and click Manage Inventory
5. Game immediately crashes
6. Reloading the game puts you back at end of fight minus the treasure found in step 4.
This has happened to me twice already. What I do now is after creating the save portal, enter the dungeon and close the game and reload. This seems to fix the problem. Both time game crashed and I lost treasure on at start of game on first level so no biggie. I just worried this would happen later on in a game that I find Sword +5 or something, then that would be a game over for me.