Actually remove the unknown entity id. Not the known entity ids..

src/me/libraryaddict/disguise/utilities/DisguiseUtilities.java

@@ -263,7 +263,7 @@ public class DisguiseUtilities {
         }
         return null;
     }
-
+    
     public static TargetedDisguise getDisguise(Player observer, Entity entity) {
         UUID entityId = entity.getUniqueId();
         if (futureDisguises.containsKey(entity.getEntityId())) {
@@ -293,6 +293,10 @@ public class DisguiseUtilities {
         return new TargetedDisguise[0];
     }
 
+    public static HashMap<Integer, HashSet<TargetedDisguise>> getFutureDisguises() {
+        return futureDisguises;
+    }
+
     public static Object getGameProfile(String playerName) {
         return gameProfiles.get(playerName);
     }