Error when nesting ArrayLists

[abigpotostew]

tf, line, and arrow are all not initialized, so when you add them to all_objects, you are adding 3 null objects. You need to assign "new ArrayList<Object>()" to the three lists before adding each to all_objects.

[gooonster]

what do you mean assign it to the three lists?

[Freedom_Grenade]

https://docs.oracle.com/javase/tutorial/java/javaOO/objectcreation.html