java.lang.NullPointerException: Ticking block entity
at net.minecraft.item.ItemStack.func_77972_a(ItemStack.java:270)
at ic2.core.block.machine.tileentity.TileEntityCropmatron.scan(TileEntityCropmatron.java:123)
at ic2.core.block.machine.tileentity.TileEntityCropmatron.func_145845_h(TileEntityCropmatron.java:80)
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:186)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Stacktrace:
at net.minecraft.item.ItemStack.func_77972_a(ItemStack.java:270)
at ic2.core.block.machine.tileentity.TileEntityCropmatron.scan(TileEntityCropmatron.java:123)
at ic2.core.block.machine.tileentity.TileEntityCropmatron.func_145845_h(TileEntityCropmatron.java:80)

Server Version: Cauldron Forge 1.7.10
Forge Version: 10.13.3.1403

@Dr0n1k thanks for that bugreport. To prevent that do not use WeedEx in the Cropmatron. That is causing it...

Fixed. Thanks for that report.