python 人脸识别报错问题解决

错误报错如下

Traceback (most recent call last):
  File "C:\Users\PQY\PycharmProjects\rlsb\05人脸检测.py", line 15, in <module>
    face_detect_demo()
  File "C:\Users\PQY\PycharmProjects\rlsb\05人脸检测.py", line 7, in face_detect_demo
    face = face_detect.detectMultiScale(gary,1.01,5,0,(100,100),(300,300))
cv2.error: OpenCV(4.5.4-dev) D:\a\opencv-python\opencv-python\opencv\modules\objdetect\src\cascadedetect.cpp:1689: error: (-215:Assertion failed) !empty() in function 'cv::CascadeClassifier::detectMultiScale'