My players (on 1.9, using buildingbricks 1.9-1.4.8) are experiencing random crashes when entering snowy biomes

The below is the error they all seem to receive:

java.lang.IllegalArgumentException: Cannot get property PropertyEnum{name=half, clazz=class net.minecraft.block.BlockDoublePlant$EnumBlockHalf, values=[upper, lower]} as it does not exist in BlockStateContainer{block=buildingbrickscompatvanilla:grass_slab, properties=[half, snowy]}
at net.minecraft.block.state.BlockStateContainer$StateImplementation.func_177229_b(BlockStateContainer.java:192)

I should mention these are client-side crashes. The server doesn't even blink.

On further inspection, this looks really similar to the closed bug #48, the players all also have WAILA installed... so my deepest apologies if this isn't a bug in BuildingBricks. You can feel free to close this immediately if so :/