Error vk_api.exceptions.ApiError: [100] One of the parameters specified was missing or invalid: message is empty or invalid?

Question

Python

import vk_api
import time 
token = "5843245b181ae990161384ba1e0008bd13e5b5fe993d51"
user_id = 1 
vk = vk_api.VkApi(token=token).get_api()
f = open("tt.txt", "rt", encoding="utf8")
def captcha_handler(captcha):
    key = input("Enter captcha code {0}: ".format(captcha.get_url())).strip()
    return captcha.try_again(key)

while True:
    try:
        line = f.read()
        time.sleep(1)
        vk.messages.send(
            chat_id=51,
            message=line,
            random_id=0
        )
        f.seek(0)
    except vk_api.exceptions.Captcha as captcha:
        captcha_handler(captcha)

after calling an exception and entering captcha, an error pops up:
Traceback (most recent call last):
File "C:\Users\Rik\Desktop\321.py", line 15, in
vk.messages.send(
File "C:\Users\ Rik\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\vk_api\vk_api.py", line 708, in __call__
return self._vk.method(self._method, kwargs)
File "C:\Users\Rik\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\vk_api\vk_api.py", line 668, in method
raise error
vk_api.exceptions.ApiError: [100] One of the parameters specified was missing or invalid: message is empty or invalid

Answer 1

Make sure before calling the method that the line passed to it as the message parameter is not empty.