Protect reads from world being null

src/main/java/com/raoulvdberge/refinedstorage/tile/TileBase.java

@@ -32,8 +32,10 @@ public abstract class TileBase extends TileEntity implements ITickable {
     }
 
     public void updateBlock() {
+        if (worldObj != null) {
             worldObj.notifyBlockUpdate(pos, worldObj.getBlockState(pos), worldObj.getBlockState(pos), 1 | 2);
         }
+    }
 
     public void setDirection(EnumFacing direction) {
         this.direction = direction;

src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskDrive.java

@@ -164,11 +164,9 @@ public class TileDiskDrive extends TileNode implements IItemStorageProvider, IFl
                     network.getFluidStorageCache().invalidate();
                 }
 
-                if (worldObj != null) {
                 updateBlock();
             }
         }
-        }
 
         @Override
         public ItemStack extractItem(int slot, int amount, boolean simulate) {