Issue description:

Randomly the server crashes involving Storage drawers and Refined storage external storage.

What happens:

Server Crash

What you expected to happen:

Not Crash

Steps to reproduce:

1.Attach External Storage to Storage drawers Controller.
2.????
3.Profit
...

Version (Make sure you are on the latest version before reporting):

• Minecraft: 1.10.2
• Forge: 12.18.3.2185
• Refined Storage: 1.2.14

Does this issue occur on a server? [yes]

If a (crash)log is relevant for this issue, link it here:

java.lang.NullPointerException: Ticking block entity
at com.raoulvdberge.refinedstorage.tile.externalstorage.ItemStorageDrawerGroup.extractItem(ItemStorageDrawerGroup.java:103)
at com.raoulvdberge.refinedstorage.tile.TileController.extractItem(TileController.java:692)
at com.raoulvdberge.refinedstorage.tile.TileInterface.updateNode(TileInterface.java:82)
at com.raoulvdberge.refinedstorage.tile.TileNode.func_73660_a(TileNode.java:79)
at org.spongepowered.common.event.tracking.TrackingUtil.tickTileEntity(TrackingUtil.java:212)
at net.minecraft.world.WorldServer.updateTileEntity(WorldServer.java:1344)
at net.minecraft.world.WorldServer.redirect$onUpdateTileEntities$zjl000(WorldServer.java:1331)
at net.minecraft.world.World.func_72939_s(World.java:1282)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:721)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:709)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:387)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:613)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:471)
at java.lang.Thread.run(Thread.java:745)

Update! This was fixed in the latest versions of RS.