diff --git a/src/com/massivecraft/massivecore/store/Coll.java b/src/com/massivecraft/massivecore/store/Coll.java
index 1b9c9a9c..c71b2483 100644
--- a/src/com/massivecraft/massivecore/store/Coll.java
+++ b/src/com/massivecraft/massivecore/store/Coll.java
@@ -344,7 +344,6 @@ public class Coll<E extends Entity<E>> extends CollAbstract<E>
 			
 			// Then attach!
 			this.attach(entity, id, false);
-			
 			// On creation it might be modified by addition or removal of new/old fields.
 			// So we must do a check for that.
 			// this.putIdentifiedModificationFixed(id, Modification.UNKNOWN);
diff --git a/src/com/massivecraft/massivecore/store/EntityContainerAbstract.java b/src/com/massivecraft/massivecore/store/EntityContainerAbstract.java
index e819fc23..ef8c701e 100644
--- a/src/com/massivecraft/massivecore/store/EntityContainerAbstract.java
+++ b/src/com/massivecraft/massivecore/store/EntityContainerAbstract.java
@@ -244,8 +244,8 @@ public abstract class EntityContainerAbstract<E extends EntityInternal<E>> imple
 	protected synchronized String attach(E entity, Object oid, boolean noteModification)
 	{
 		// Check entity
-		if (entity == null) return null;
-		if (entity.attached()) return entity.getId();
+		if (entity == null) throw new NullPointerException("entity");
+		if (entity.attached()) throw new IllegalArgumentException("already attached");
 		
 		String id;
 		// Check/Fix id
@@ -259,7 +259,7 @@ public abstract class EntityContainerAbstract<E extends EntityInternal<E>> imple
 			if (id == null) return null;
 			if (this.getIdToEntity().containsKey(id)) return null;
 		}
-		
+
 		// PRE
 		this.preAttach(entity, id);
 		
@@ -269,7 +269,6 @@ public abstract class EntityContainerAbstract<E extends EntityInternal<E>> imple
 		
 		// Attach
 		this.getIdToEntityRaw().put(id, entity);
-		
 		// Identify Modification
 		if (noteModification)
 		{