If I have ANY pre-0.16 worlds in the worlds folder, the game crashes upon open, except the FIRST time that it is opened after a reboot. If I delete all my pre-0.16 worlds, the game functions perfectly fine.

Testing for issue MCPE-14551 (https://bugs.mojang.com/browse/MCPE-14551) I found that if I have any PRE 0.16 worlds in the worlds folder, upon closing MCPE and re-opening it, the game consistently crashes JUST as the first Main menu appears. If I remove those PRE-0.16 worlds, then reboot, the game behaves as expected. I can open, close, open, close as many times as I want without issue.

In fact even the MCPE-14551 issues disappear - however this issue goes away ONLY for 0.16 worlds.

If I have pre 0.16 worlds (last saved with 0.15.10), the game will open ONCE after a reboot. Then, if I close the game and try to re-open it, it will crash continuously upon open. After removing the older worlds, rebooting, the game goes back to proper operation.

NOTE: I am ONLY removing or adding WORLDS. I am NOT touching any other files (such as configuration information,etc.).