Python tkinter creating two windows

I am currently trying to create two windows with a tkinter program but it doesn't seem to be working. It was only recently that i just moved over my game to tkinter and it is the first time working with tkinter. Due to that I have no clue why this isn't working.

This is my first window and its working fine

class Application(tk.Frame):
        def __init__(self, master=None):
            super().__init__(master)
            self.pack()
            self.create_widgets()
            self.crafting_listbox

My second window though isn't working

class Application_2(tk.Frame):
        def __init__(self, master=None):
            super().__init__(master)
            self.pack()
            self.crafting_listbox()

Then the finishing bit

 root = tk.Tk()
    app = Application(master=root)
    app.mainloop()

I am unsure why this isn't working, whats going wrong?