Windows not working cap.cpp (265) cv::VideoCapture::open VIDEOIO(DSHOW): raised unknown C++ exception!

[chrapacz2000]

[ERROR:0] global C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-9d_dfo3_\opencv\modules\videoio\src\cap.cpp (265) cv::VideoCapture::open VIDEOIO(DSHOW): raised unknown C++ exception!

Traceback (most recent call last):
File "demo.py", line 219, in
main()
File "demo.py", line 62, in main
pose_estimator = PoseEstimator(img_size=sample_frame.shape[:2])
AttributeError: 'NoneType' object has no attribute 'shape'

When i've launched the script first time it was working fine and perfect, now it is broken, i didn't modify anything