Trying to open image with pysimplegui, but getting error window pop up

Question

I am following this tutorial to try and get an image to show up in a window with pysimplegui. https://www.youtube.com/watch?v=KtlGrgWf6Y8

import PySimpleGUI as sg
import os

layout = [
            [sg.Image(filename='test_image_2.png')],
            [sg.Button('Exit')]
        ]

window = sg.Window("Image Viewer", layout)

while True:
        event, values = window.read()
        if event == "Exit" or event == sg.WIN_CLOSED:
            break

window.close()

I use the same code that the teacher uses, and the same image file and saved in the same folder as the python file. When i run the code, I get the following window pop up: error pop up window

I cannot understand why this would be showing. Do i need to save the image file to a different location? Or is it something else?