MAP bug

bug of the maps. 0.14.3 maps work-0.15.0-0.15.4 maps do not work.

problem is in multiplayer. and the error is not in the software PocketMine-MP.
the error is in MCPE

0.11.X - 0.14.3 HAVE SUPPORT ANVIL WORLD
0.15.0 - 0.15.6 ID NOT HAVE SUPPORT ANVIL WORLD

BUG is on the all mobile/tablet