TypeError: argument of type 'NoneType' is not iterable

[Purushottam-BCA]

Although i have followed all the steps mentioned but still i am getting this error.

File "whatsoup.py", line 1104, in
main()
File "whatsoup.py", line 21, in main
driver = setup_selenium()
File "whatsoup.py", line 90, in setup_selenium
executable_path=DRIVER_PATH, options=options)
File "C:\Users\pk199\Desktop\final-project\Other\WhatsApp-Scrape\WhatSoup\env\lib\site-packages\selenium\webdriver\chrome\webdriver.py", line 73, in init
self.service.start()
File "C:\Users\pk199\Desktop\final-project\Other\WhatsApp-Scrape\WhatSoup\env\lib\site-packages\selenium\webdriver\common\service.py", line 76,
in start
stdin=PIPE)
File "C:\Users\pk199\AppData\Local\Programs\Python\Python37\lib\subprocess.py", line 756, in init
restore_signals, start_new_session)
File "C:\Users\pk199\AppData\Local\Programs\Python\Python37\lib\subprocess.py", line 1100, in _execute_child
args = list2cmdline(args)
File "C:\Users\pk199\AppData\Local\Programs\Python\Python37\lib\subprocess.py", line 511, in list2cmdline
needquote = (" " in arg) or ("\t" in arg) or not arg
TypeError: argument of type 'NoneType' is not iterable.