Fixed serversided issue. Forgot to check for uses of isEnabled before changing it to a clientside only method.

src/main/java/appeng/client/gui/AEBaseGui.java

@@ -251,7 +251,7 @@ public abstract class AEBaseGui extends GuiContainer
 				final OptionalSlotFake fs = (OptionalSlotFake) slot;
 				if( fs.renderDisabled() )
 				{
-					if( fs.isEnabled() )
+					if( fs.isSlotEnabled() )
 					{
 						this.drawTexturedModalRect( ox + fs.xPos - 1, oy + fs.yPos - 1, fs.getSourceX() - 1, fs.getSourceY() - 1, 18,
 								18 );

src/main/java/appeng/container/implementations/ContainerUpgradeable.java

@@ -204,7 +204,7 @@ public class ContainerUpgradeable extends AEBaseContainer implements IOptionalSl
 			if( o instanceof OptionalSlotFake )
 			{
 				final OptionalSlotFake fs = (OptionalSlotFake) o;
-				if( !fs.isEnabled() && !fs.getDisplayStack().isEmpty() )
+				if( !fs.isSlotEnabled() && !fs.getDisplayStack().isEmpty() )
 				{
 					fs.clearStack();
 				}

src/main/java/appeng/container/slot/AppEngSlot.java

@@ -26,6 +26,8 @@ import net.minecraft.item.ItemStack;
 
 import appeng.container.AEBaseContainer;
 import appeng.tile.inventory.AppEngInternalInventory;
+import net.minecraftforge.fml.relauncher.Side;
+import net.minecraftforge.fml.relauncher.SideOnly;
 
 import javax.annotation.Nonnull;
 
@@ -75,7 +77,7 @@ public class AppEngSlot extends Slot
 	@Override
 	public boolean isItemValid( final ItemStack par1ItemStack )
 	{
-		if( this.isEnabled() )
+		if( this.isSlotEnabled() )
 		{
 			return super.isItemValid( par1ItemStack );
 		}
@@ -86,7 +88,7 @@ public class AppEngSlot extends Slot
 	@Nonnull
 	public ItemStack getStack()
 	{
-		if( !this.isEnabled() )
+		if( !this.isSlotEnabled() )
 		{
 			return ItemStack.EMPTY;
 		}
@@ -107,7 +109,7 @@ public class AppEngSlot extends Slot
 	@Override
 	public void putStack( final ItemStack par1ItemStack )
 	{
-		if( this.isEnabled() )
+		if( this.isSlotEnabled() )
 		{
 			super.putStack( par1ItemStack );
 
@@ -136,7 +138,7 @@ public class AppEngSlot extends Slot
 	@Override
 	public boolean canTakeStack( final EntityPlayer par1EntityPlayer )
 	{
-		if( this.isEnabled() )
+		if( this.isSlotEnabled() )
 		{
 			return super.canTakeStack( par1EntityPlayer );
 		}
@@ -144,11 +146,17 @@ public class AppEngSlot extends Slot
 	}
 
 	@Override
+	@SideOnly( Side.CLIENT )
 	public boolean isEnabled()
 	{
 		return super.isEnabled();
 	}
 
+	public boolean isSlotEnabled()
+	{
+		return true;
+	}
+
 	public ItemStack getDisplayStack()
 	{
 		return super.getStack();
@@ -176,7 +184,7 @@ public class AppEngSlot extends Slot
 
 	public boolean shouldDisplay()
 	{
-		return this.isEnabled();
+		return this.isSlotEnabled();
 	}
 
 	public int getX()

src/main/java/appeng/container/slot/OptionalSlotFake.java

@@ -47,7 +47,7 @@ public class OptionalSlotFake extends SlotFake
 	@Nonnull
 	public ItemStack getStack()
 	{
-		if( !this.isEnabled() )
+		if( !this.isSlotEnabled() )
 		{
 			if( !this.getDisplayStack().isEmpty() )
 			{
@@ -59,7 +59,7 @@ public class OptionalSlotFake extends SlotFake
 	}
 
 	@Override
-	public boolean isEnabled()
+	public boolean isSlotEnabled()
 	{
 		if( this.host == null )
 		{

src/main/java/appeng/container/slot/OptionalSlotNormal.java

@@ -36,7 +36,7 @@ public class OptionalSlotNormal extends AppEngSlot
 	}
 
 	@Override
-	public boolean isEnabled()
+	public boolean isSlotEnabled()
 	{
 		if( this.host == null )
 		{

src/main/java/appeng/container/slot/OptionalSlotRestrictedInput.java

@@ -37,7 +37,7 @@ public class OptionalSlotRestrictedInput extends SlotRestrictedInput
 	}
 
 	@Override
-	public boolean isEnabled()
+	public boolean isSlotEnabled()
 	{
 		if( this.host == null )
 		{

src/main/java/appeng/container/slot/SlotPatternOutputs.java

@@ -31,7 +31,7 @@ public class SlotPatternOutputs extends OptionalSlotFake
 	}
 
 	@Override
-	public boolean isEnabled()
+	public boolean isSlotEnabled()
 	{
 		return true;
 	}
@@ -39,6 +39,6 @@ public class SlotPatternOutputs extends OptionalSlotFake
 	@Override
 	public boolean shouldDisplay()
 	{
-		return super.isEnabled();
+		return super.isSlotEnabled();
 	}
 }

src/main/java/appeng/container/slot/SlotPatternTerm.java

@@ -56,7 +56,7 @@ public class SlotPatternTerm extends SlotCraftingTerm
 	@Override
 	public ItemStack getStack()
 	{
-		if( !this.isEnabled() )
+		if( !this.isSlotEnabled() )
 		{
 			if( !this.getDisplayStack().isEmpty() )
 			{
@@ -68,7 +68,7 @@ public class SlotPatternTerm extends SlotCraftingTerm
 	}
 
 	@Override
-	public boolean isEnabled()
+	public boolean isSlotEnabled()
 	{
 		if( this.host == null )
 		{