Oh man Mojang..

Whats wrong with your register Block class?

Its really messed up and unsorted.

In the beginnings, they are listed from highest id to lowest id.

(you have to read from bottom to top)

Sand
StillLava
FlowingLava
StillWater
FlowingWater
Bedrock
Sapling
WoodPlanks
Cobblestone
Dirt
Grass
Stone
Air

But then, especially after id 127 (Lit redstone lamp) the class really messed up.

EmeraldOre // thats 129.. wheres EmeraldBlock, the 130?
Cocoa // Where is activator rail?
LitRedStoneLamp

NetherBrickStairs
NetherBrick // okay.. its next to nether brick stair.. but..
StoneBrickStairs
DarkOakStairs
AcaciaStairs
WoodButton // WHY IN HOLY SKY BIOME IS THIS HERE?!
JungleStairs
BirchStairs
SpruceStairs

How it actually should be looking like:

REDSTONE_LAMP = 123
LIT_REDSTONE_LAMP = 124
ACTIVATOR_RAIL = 126
COCOA = 127
SANDSTONE_STAIRS = 128
EMERALD_ORE = 129
ENDERCHEST = 130 //?
TRIPWIRE_HOOK = 131
TRIPWIRE = 132
EMERALD_BLOCK = 133
SPRUCE_WOOD_STAIRS = 134
BIRCH_WOOD_STAIRS = 135
JUNGLE_WOOD_STAIRS = 136

I know, this no actual "bug".. but thats bad practice i think. A cleanup will maybe help you in future development, due to MCPE being a GREAT project.

I am glad if i was able to help you a bit. Thanks ^^