bgerror failed to handle background error

[UTexasRepo]

Desktop (please complete the following information):

ttkbootstrap Version [e.g. 1.10.1]
OS: [e.g. Windows]

Describe the bug

I ran a simple app and am receiving bg error when I exit the program.

To Reproduce

A No Frills superhero theme

from tkinter import *
from ttkbootstrap.constants import *
import ttkbootstrap as tb

root = tb.Window(themename = "superhero")
root.title("TTK Bootstrap!")
root.geometry('500x350')

root.mainloop()

Expected behavior

When I exit the program, I do not expect this behavior.

Screenshots

The application runs fine

The application when exited, producing the following error:

Additional context

No response