!_src.empty() in function 'cvtColor'

[BIGG000]

Hey,
Getting this error while using this code, so please check it out or give me an answer that how could I do correct it.

`error Traceback (most recent call last)
in
11 ret, frame = video_capture.read()
12
---> 13 gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
14
15 faces = faceCascade.detectMultiScale(

error: OpenCV(4.4.0) /tmp/pip-req-build-cg56sov1/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

​​`