I have a program that does mass spec data reduction. The workflow is:

1. Present the user with a list of sequences, and ask them to select a sequence from the list.
2. Once a sequence of analyses has been selected, the user is presented with a plot of the raw data to analyze.

For a while, this transition between the sequence selector GUI and the raw data GUI has been generating a cryptic error which looks like:

invalid command name "2073977167560update"
    while executing
"2073977167560update"
    ("after" script)
invalid command name "2073972183304check_dpi_scaling"
    while executing
"2073972183304check_dpi_scaling"
    ("after" script)

I have no idea what this means. Last time I saw it, I was using matplotlib.pyplot instead of matplotlib.figure in conjunction with tkinter. This time, I suspect it has to do with the transition between the GUIs, but I have no idea what I’m doing wrong or what I should be doing differently.

Here’s a minimal reproducible example:

from tkinter import ttk
import customtkinter as ctk
import matplotlib.figure as Figure
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

def create_first_gui():
    window = ctk.CTk()
    window.title('First GUI')

    tree = ttk.Treeview(window)
    tree["columns"]=("one","two")
    tree.column("#0", width=100)
    tree.column("one", width=100)
    tree.column("two", width=100)
    tree.heading("#0",text="Column A")
    tree.heading("one", text="Column B")
    tree.heading("two", text="Column C")

    tree.insert("", 0, text="Line 1", values=("Random 1","Random 2"))

    tree.pack()

    button = ctk.CTkButton(window, text="Proceed to Second GUI", command=window.destroy)
    button.pack()

    window.mainloop()

def create_second_gui():
    window = ctk.CTk()
    window.title('Second GUI')

    fig = Figure.Figure(figsize=(5, 4), dpi=100)
    t = [i/100 for i in range(100)]
    fig.add_subplot(111).plot(t, [i**2 for i in t])

    canvas = FigureCanvasTkAgg(fig, master=window)
    canvas.draw()
    canvas.get_tk_widget().pack(side=ctk.TOP, fill=ctk.BOTH, expand=1)

    window.mainloop()

create_first_gui()
create_second_gui()

The above script also produces a “click_animation” error:

invalid command name "2224692384648update"
    while executing
"2224692384648update"
    ("after" script)
invalid command name "2224697676232check_dpi_scaling"
    while executing
"2224697676232check_dpi_scaling"
    ("after" script)
invalid command name "2224697708616_click_animation"
    while executing
"2224697708616_click_animation"
    ("after" script)