World Loads then crashes in specific area / starting with 1.6 update.

Hi,

My son's Minecraft world loads and then Minecraft quits the character move to a certain area of his map.  This seems to have been an issue since Minecraft 1.6.   I tried this on my iPhone SE, same issue.

Transferred the saved game to Windows 10 Minecraft and could not reproduce the issue.

Furthermore, the same occurs on a saved map that I backed up in mid August.  He's been playing the game fine up until yesterday when the issues began, though he hadn't played the game since the 1.6 update.

( I've tried attaching the game file(s) but they exceed 10MB limit )

Thank you,