Access Violation Exception Thrown OpenCV - c++

Question

Im working on a simple face detector using Visual Studio 2017 with OpenCV 3.2.0 and haarcascades.
Whenever i run this, i get an error saying there's an exception thrown right after i create the first point. Access violation error. Any help would be greatly appreciated as I do not see any error in the code.
#include <opencv2/opencv.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <stdio.h>
#include <vector>
using namespace std;
using namespace cv;
int main()
{
CascadeClassifier face_cascade;
CascadeClassifier eye_cascade;
face_cascade.load("haarcascade_frontalface_alt.xml");
eye_cascade.load("haarcascade_eye_tree_eyeglasses.xml");
VideoCapture cap(0);
Mat frame;
while (cap.read(frame))
{
Mat frame_gray;
std::vector <Rect> faces;
cvtColor(frame, frame_gray, COLOR_BGR2GRAY);
equalizeHist(frame_gray, frame_gray);
face_cascade.detectMultiScale(frame_gray,faces, 1.1, 2,0,Size(30,30),Size(300,300));
for (size_t i = 0; i < faces.size();i++)
{
Point first(faces[i].x, faces[i].y);
Point second(faces[i].x + faces[i].width, faces[i].y + faces[i].height);
rectangle(frame,second,first, cvScalar(255, 0, 0), 1, 8, 0);
}
imshow("Test", frame_gray);
waitKey(30);
}
return 0;
}