Temporary hack to fix age throwing errors, don't give every NPC age on create

src/main/java/net/citizensnpcs/command/command/NPCCommands.java

@@ -204,6 +204,7 @@ public class NPCCommands {
         npc.spawn(player.getLocation());
 
         // Set age after entity spawns
+        if (npc.getBukkitEntity() instanceof Ageable)
             npc.getTrait(Age.class).setAge(age);
 
         selector.select(player, npc);

src/main/java/net/citizensnpcs/trait/Age.java

@@ -10,6 +10,7 @@ import org.bukkit.entity.Ageable;
 public class Age extends Trait implements Runnable, Toggleable {
     private int age = 0;
     private boolean locked = true;
+    private boolean ageable = false;
     private final NPC npc;
 
     public Age(NPC npc) {
@@ -26,14 +27,18 @@ public class Age extends Trait implements Runnable, Toggleable {
 
     @Override
     public void onNPCSpawn() {
+        if (npc instanceof Ageable) {
             Ageable entity = (Ageable) npc.getBukkitEntity();
             entity.setAge(age);
             entity.setAgeLock(locked);
+            ageable = true;
+        } else
+            ageable = false;
     }
 
     @Override
     public void run() {
-        if (!locked)
+        if (!locked && ageable)
             age = ((Ageable) npc.getBukkitEntity()).getAge();
     }
 
@@ -45,12 +50,14 @@ public class Age extends Trait implements Runnable, Toggleable {
 
     public void setAge(int age) {
         this.age = age;
+        if (ageable)
             ((Ageable) npc.getBukkitEntity()).setAge(age);
     }
 
     @Override
     public boolean toggle() {
         locked = !locked;
+        if (ageable)
             ((Ageable) npc.getBukkitEntity()).setAgeLock(locked);
         return locked;
     }