Remember to perform deep cloning.

ProtocolLib/dependency-reduced-pom.xml

@@ -4,7 +4,7 @@
   <groupId>com.comphenix.protocol</groupId>
   <artifactId>ProtocolLib</artifactId>
   <name>ProtocolLib</name>
-  <version>1.8.0-SNAPSHOT</version>
+  <version>1.8.0</version>
   <description>Provides read/write access to the Minecraft protocol.</description>
   <url>http://dev.bukkit.org/server-mods/protocollib/</url>
   <developers>

ProtocolLib/src/main/java/com/comphenix/protocol/wrappers/WrappedDataWatcher.java

@@ -300,7 +300,7 @@ public class WrappedDataWatcher implements Iterable<WrappedWatchableObject> {
     	
     	// Make a new copy instead
     	for (WrappedWatchableObject watchable : this) {
-    		clone.setObject(watchable.getIndex(), watchable.getValue());
+    		clone.setObject(watchable.getIndex(), watchable.getClonedValue());
     	}
     	return clone;
     }

ProtocolLib/src/main/java/com/comphenix/protocol/wrappers/WrappedWatchableObject.java

@@ -307,7 +307,7 @@ public class WrappedWatchableObject {
 	}
 	
 	// Helper
-	private Object getClonedValue() throws FieldAccessException {
+	Object getClonedValue() throws FieldAccessException {
 		Object value = getValue();
 		
 		// Only a limited set of references types are supported