I am also experiencing this crashing issue on a 1.21.30 local PC world. The crash will also happen on a brand new 1.21.30 world and added no resource packs.
I can consistently cause the crash to occur when using the right-hand slot with paper.
If I put in emeralds and books, the game does not crash. If I put paper into the left-hand slot, the game does not crash. After putting paper into the right-hand slot and on the fourth trade, the game is guaranteed to crash.
@Jeanliang - make sure Minecraft is not running (maybe restart your iPad), then using the Files app, copy the folder back to the iPad. This is what I did to backup and restore the worlds my son has created.
I am also experiencing this crashing issue on a 1.21.30 local PC world. The crash will also happen on a brand new 1.21.30 world and added no resource packs.
I can consistently cause the crash to occur when using the right-hand slot with paper.
If I put in emeralds and books, the game does not crash. If I put paper into the left-hand slot, the game does not crash. After putting paper into the right-hand slot and on the fourth trade, the game is guaranteed to crash.
I have video recordings if needed.