When generating a world set to default, BoP comes up with this crash:

Description: Exception in server tick loop

java.lang.RuntimeException: Failed to find GenLayerBiome in chain
at biomesoplenty.common.eventhandler.world.DefaultWorldEventHandler.onInitBiomeGens(DefaultWorldEventHandler.java:46)
at cpw.mods.fml.common.eventhandler.ASMEventHandler_14_DefaultWorldEventHandler_onInitBiomeGens_InitBiomeGens.invoke(.dynamic)
at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:51)
at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:122)
at net.minecraft.world.biome.WorldChunkManager.getModdedBiomeGenerators(WorldChunkManager.java:249)
at net.minecraft.world.biome.WorldChunkManager.(WorldChunkManager.java:41)
at net.minecraft.world.chunk.storage.AnvilSaveConverter.func_75805_a(SourceFile:129)
at net.minecraft.server.MinecraftServer.func_71237_c(MinecraftServer.java:154)
at net.minecraft.server.integrated.IntegratedServer.func_71247_a(IntegratedServer.java:59)
at net.minecraft.server.integrated.IntegratedServer.func_71197_b(IntegratedServer.java:92)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:374)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:665)

Fixed with the latest commit.