diff --git a/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/AddlineCommand.java b/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/AddlineCommand.java
index 9852722a..5ac1049e 100644
--- a/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/AddlineCommand.java
+++ b/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/AddlineCommand.java
@@ -4,6 +4,7 @@ import java.util.Arrays;
 import java.util.List;
 
 import org.bukkit.Bukkit;
+import org.bukkit.Material;
 import org.bukkit.command.CommandSender;
 
 import com.gmail.filoghost.holographicdisplays.commands.Colors;
@@ -15,6 +16,7 @@ import com.gmail.filoghost.holographicdisplays.event.NamedHologramEditedEvent;
 import com.gmail.filoghost.holographicdisplays.exception.CommandException;
 import com.gmail.filoghost.holographicdisplays.object.NamedHologram;
 import com.gmail.filoghost.holographicdisplays.object.NamedHologramManager;
+import com.gmail.filoghost.holographicdisplays.util.ItemUtils;
 import com.gmail.filoghost.holographicdisplays.util.Utils;
 
 public class AddlineCommand extends HologramSubCommand {
@@ -38,8 +40,21 @@ public class AddlineCommand extends HologramSubCommand {
 	public void execute(CommandSender sender, String label, String[] args) throws CommandException {
 		NamedHologram hologram = NamedHologramManager.getHologram(args[0].toLowerCase());
 		CommandValidator.notNull(hologram, Strings.noSuchHologram(args[0].toLowerCase()));
+		String line = Utils.join(args, " ", 1, args.length);
+		
+		// Check material validity
+		if (line.toLowerCase().startsWith("icon:")) {
+			String iconMaterial = ItemUtils.stripSpacingChars(line.substring("icon:".length(), line.length()));
+			
+			if (iconMaterial.contains(":")) {
+				iconMaterial = iconMaterial.split(":")[0];
+			}
+			
+			Material mat = ItemUtils.matchMaterial(iconMaterial);
+			CommandValidator.notNull(mat, "Invalid icon material.");
+		}
 
-		hologram.getLinesUnsafe().add(HologramDatabase.readLineFromString(Utils.join(args, " ", 1, args.length), hologram));
+		hologram.getLinesUnsafe().add(HologramDatabase.readLineFromString(line, hologram));
 		hologram.refreshAll();
 			
 		HologramDatabase.saveHologram(hologram);
diff --git a/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/SetlineCommand.java b/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/SetlineCommand.java
index 02b65a96..382571e6 100644
--- a/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/SetlineCommand.java
+++ b/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/commands/main/subs/SetlineCommand.java
@@ -4,6 +4,7 @@ import java.util.Arrays;
 import java.util.List;
 
 import org.bukkit.Bukkit;
+import org.bukkit.Material;
 import org.bukkit.command.CommandSender;
 
 import com.gmail.filoghost.holographicdisplays.commands.Colors;
@@ -15,6 +16,7 @@ import com.gmail.filoghost.holographicdisplays.event.NamedHologramEditedEvent;
 import com.gmail.filoghost.holographicdisplays.exception.CommandException;
 import com.gmail.filoghost.holographicdisplays.object.NamedHologram;
 import com.gmail.filoghost.holographicdisplays.object.NamedHologramManager;
+import com.gmail.filoghost.holographicdisplays.util.ItemUtils;
 import com.gmail.filoghost.holographicdisplays.util.Utils;
 
 public class SetlineCommand extends HologramSubCommand {
@@ -39,14 +41,26 @@ public class SetlineCommand extends HologramSubCommand {
 	public void execute(CommandSender sender, String label, String[] args) throws CommandException {
 		NamedHologram hologram = NamedHologramManager.getHologram(args[0].toLowerCase());
 		CommandValidator.notNull(hologram, Strings.noSuchHologram(args[0].toLowerCase()));
+		String line = Utils.join(args, " ", 2, args.length);
 		
+		// Check material validity
+		if (line.toLowerCase().startsWith("icon:")) {
+			String iconMaterial = ItemUtils.stripSpacingChars(line.substring("icon:".length(), line.length()));
 			
+			if (iconMaterial.contains(":")) {
+				iconMaterial = iconMaterial.split(":")[0];
+			}
+					
+			Material mat = ItemUtils.matchMaterial(iconMaterial);
+			CommandValidator.notNull(mat, "Invalid icon material.");
+		}
+		
 		int lineNumber = CommandValidator.getInteger(args[1]);
 		CommandValidator.isTrue(lineNumber >= 1 && lineNumber <= hologram.size(), "The line number must be between 1 and " + hologram.size() + ".");
 		int index = lineNumber - 1;
 		
 		hologram.getLinesUnsafe().get(index).despawn();
-		hologram.getLinesUnsafe().set(index, HologramDatabase.readLineFromString(Utils.join(args, " ", 2, args.length), hologram));
+		hologram.getLinesUnsafe().set(index, HologramDatabase.readLineFromString(line, hologram));
 		hologram.refreshAll();
 
 		HologramDatabase.saveHologram(hologram);
diff --git a/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/nms/v1_8_R2/EntityNMSItem.java b/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/nms/v1_8_R2/EntityNMSItem.java
index 2ca53e39..cdbc7a98 100644
--- a/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/nms/v1_8_R2/EntityNMSItem.java
+++ b/HolographicDisplays/Plugin/com/gmail/filoghost/holographicdisplays/nms/v1_8_R2/EntityNMSItem.java
@@ -103,6 +103,15 @@ public class EntityNMSItem extends EntityItem implements NMSItem {
 		 */
 	    return true;
 	}
+	
+	@Override
+	public void inactiveTick() {
+		// Check inactive ticks.
+		
+		if (!lockTick) {
+			super.inactiveTick();
+		}
+	}
 
 	@Override
 	public void setLockTick(boolean lock) {
@@ -111,6 +120,8 @@ public class EntityNMSItem extends EntityItem implements NMSItem {
 	
 	@Override
 	public void die() {
+		System.out.println("Hologram Item died:");
+		Thread.dumpStack();
 		setLockTick(false);
 		super.die();
 	}
diff --git a/HolographicDisplays/plugin.yml b/HolographicDisplays/plugin.yml
index 82eab663..283252da 100644
--- a/HolographicDisplays/plugin.yml
+++ b/HolographicDisplays/plugin.yml
@@ -1,6 +1,6 @@
 name: HolographicDisplays
 main: com.gmail.filoghost.holographicdisplays.HolographicDisplays
-version: 2.1.7
+version: 2.1.8
 
 softdepend: [Multiverse-Core, MultiWorld, My Worlds, My_Worlds, ProtocolLib]