Hi 5M1Sec ,
Sorry about the delay. I think we know what this is now. Can you try running the following?
python3 -c "import cv2; import numpy as np; blank_image = np.zeros((500,500,3), np.uint8); cv2.imshow('s', blank_image); cv2.waitKey(0)"
I think the OpenCV install either didn't go through or was corrupted.
If this does not show a window, please run this command:
sudo curl -fL http://docs.luxonis.com/_static/install_dependencies.sh | bash
Thanks,
Brandon