Python Kivy App fails to run on second machine

Question

I've packaged my Kivy App with PyInstaller with the following cmd line: pyinstaller --onefile -w --icon=Pi.ico --add-data TheGUI.kv;. main.py

I had to copy some libraries to my dist directory in order for my .exe to work. I used this youtube video for help, for me it works perfectly fine. I didn't make any changes to my spec file, it looks like this:

# -*- mode: python ; coding: utf-8 -*-


block_cipher = None


a = Analysis(['main.py'],
             pathex=['C:\\Users\\... here is the pyth to my directory '],
             binaries=[],
             datas=[('TheGUI.kv', '.')],
             hiddenimports=[],
             hookspath=[],
             hooksconfig={},
             runtime_hooks=[],
             excludes=[],
             win_no_prefer_redirects=False,
             win_private_assemblies=False,
             cipher=block_cipher,
             noarchive=False)
pyz = PYZ(a.pure, a.zipped_data,
             cipher=block_cipher)

exe = EXE(pyz,
          a.scripts,
          a.binaries,
          a.zipfiles,
          a.datas,  
          [],
          name='main',
          debug=False,
          bootloader_ignore_signals=False,
          strip=False,
          upx=True,
          upx_exclude=[],
          runtime_tmpdir=None,
          console=False,
          disable_windowed_traceback=False,
          target_arch=None,
          codesign_identity=None,
          entitlements_file=None , icon='Pi.ico')

My .exe file runs perfectly on my laptop, but if I try to run my app on a virtual PC with Windows 10, I get

Failed to execute script 'main' due to unhandled exception: 'NoneType' object has no attribute 'size'

Failed to obtain/convert traceback!

I also tried to run the python code from the command line on the virtual PC and it works just fine. I only get this error if I try to start the .exe file.

The 'size' in the error refers to the first line in my code:

import os
import sys

from kivy.app import App
from kivy.properties import StringProperty, BooleanProperty
from kivy.uix.boxlayout import BoxLayout
import socket
import re
import threading
from kivy.core.window import Window
import socket_names

Window.size = (1300, 700)

I know there is a similar question, but the problem is not quite the same.

Anyone had the same problem, or a similar one?