SS２-2.0.9から2.1.1への更新でのエラー

java.lang.ClassCastException: shift.sextiarysector.block.BlockSSFarmland cannot be cast to shift.sextiarysector.api.agriculture.IFarmland
    at shift.sextiarysector.tileentity.TileEntitySSCrop.getFarmland(TileEntitySSCrop.java:135)
    at shift.sextiarysector.tileentity.TileEntitySSCrop.getTankInfo(TileEntitySSCrop.java:227)
    at buildcraft.transport.PipeTransportFluids.canPipeConnect(PipeTransportFluids.java:539)
    at buildcraft.transport.Pipe.canPipeConnect(Pipe.java:164)
    at buildcraft.transport.TileGenericPipe.canPipeConnect_internal(TileGenericPipe.java:747)
    at buildcraft.transport.TileGenericPipe.canPipeConnect(TileGenericPipe.java:770)
    at buildcraft.transport.TileGenericPipe.computeConnections(TileGenericPipe.java:788)
    at buildcraft.transport.TileGenericPipe.initialize(TileGenericPipe.java:582)
    at buildcraft.transport.TileGenericPipe.func_145845_h(TileGenericPipe.java:375)
    at net.minecraft.world.World.func_72939_s(World.java:1939)
    at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489)
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
    at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:111)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
    at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)