problem arises in open cv


error Traceback (most recent call last)
~\AppData\Local\Temp\ipykernel_24712\2306117373.py in
----> 1 face=face_cascade.detectMultiScale(gray,1.08, 0)

error: OpenCV(4.7.0) D:\a\opencv-python\opencv-python\opencv\modules\objdetect\src\cascadedetect.cpp:1689: error: (-215:Assertion failed) !empty() in function ‘cv::CascadeClassifier::detectMultiScale’