[Tkinter] tkinter freezes by clicking button

[Gribouillis]

Unfortunately the "solve" button is broken again: By clicking solve, another instance of tkinter is opened and it is stuck in an endless loop.

I know very little of the issues of the multiprocessing module in windows, but you could try to call freeze_support() in your code

# SudokuSolver_main.py
from multiprocessing import freeze_support
 
if __name__ == '__main__':
    freeze_support()
    import SudokuSolver_class as Sudokuolver
    from tkinter import Tk
 
    def main():
        root = Tk()
        app = Sudokuolver.SudokuSolver(root)
        root.mainloop()
 
    main()