How do I save and load everything in a level?

Hi, How do I save and load the game map and all the objects in it?

I have tried using the save and load from game slot and I can save and load the player’s position but how do I save and load all the objects within the world, for example dropped items and player’s inventory(when I get round to making that)?

Here’s the blueprints so far:

Load Game:

Save Game:

Edit: I think it is something to do with making an actor list and saving that?

You must save class, coordinate and needed variables for all needed objects, like dropped items or inventory, then when loading spawn that objects and set their variables.

I have tried creating an array of actors saving that to the file and spawning them in a loop but i get an error saying that the class is null and cant be spawned: