Hello, can you do something for me? If you know how to use godot, can you go to the scripts folders for the addon (res://addons/rpg_databases_gd/Scripts) and open the character.gd script file? (this is inside the godot editor). Then, comment the lines 106 and 107. They should say:
else:
$ClassLabel/ClassText.set_item_text(i, class_data["name"])
At the top right of the screen, just below the close button. I'm really sorry for the late answer.