cannot use geometry manager pack inside . which already has slaves managed by grid

This error occurs when you try to use the pack geometry manager on a widget that is already managed by the grid geometry manager. You cannot use both geometry managers on the same widget.

To fix this error, you need to choose one geometry manager for the widget and remove the other one. If you want to use the pack manager, remove the widget from the grid using the `grid_forget()` method before packing it. If you want to use the grid manager, remove the widget from the pack using the `pack_forget()` method before gridding it.

Here's an example of how to remove a widget from the grid and pack it:

import tkinter as tk

root = tk.Tk()

label = tk.Label(root, text="Hello, World!")
label.grid(row=0, column=0)

# Remove the label from the grid and pack it
label.grid_forget()
label.pack()

root.mainloop()