If the inventory contains at least one unequipped armor item, the game will crash if the Player dies with the armor tab open (as shown in the attached photo). This item does not have to be actively selected or in the hotbar.
Tested in survival mode with all obtainable armor types and tiers, and with death caused by mob attacks, fall damage, drowning, fire, and lava. This issue may be related to MCPE-7213

Note: during one incident all armor items were duplicated upon returning, though this is most likely a result of MCPE-396.