Trying to understand the problems in my code

I'm trying to do a function that does the following:

• Receives 3 integers from the user: size1, size2, size3.

• Creates a size1 * size2 matrix and a size2 * size3 matrix.

• Multiplies the 2 matrices.

• Prints the result matrix.

• Free all dynamic memory.

after edit and I got an error after I write two matrixs that says: Exception thrown at 0x0FA6AC1D (ucrtbased.dll) in Project8.exe: 0xC0000005: Access violation reading location 0xCCCCCCC4.

The code is:

#define _CRT_SECURE_NO_WARNINGS
#include <stdlib.h>

void BuildMatrix(int***, int, int);
void FreeMatrix(int***, int);
void PrintMatrix(int**, int, int);
int** MultiplyMatrixes(int**, int**, int, int, int);

int main() {
    int** matrix1 = NULL, ** matrix2 = NULL, ** matrix3 = NULL;
    int* newCol = NULL;
    int size1, size2, size3, newRow;

    printf("-How many rows in the first matrix?: ");
    scanf("%d", &size1);
    printf("-How many columns in the first matrix and second?[size2, size3]: ");
    scanf("%d %d", &size2, &size3);  /*size2 = rows of matrix2.*/

    /*Build both matrices*/
    printf("-First matrix input.\n");
    BuildMatrix(&matrix1, size1, size2);
    PrintMatrix(matrix1, size1, size2);
    printf("-Second matrix input.\n");
    BuildMatrix(&matrix2, size2, size3);
    PrintMatrix(matrix2, size2, size3);

    /*Combine the 2 matrices to a new matrix*/
    matrix3 = MultiplyMatrixes(matrix1, matrix2, size1, size2, size3);
    FreeMatrix(&matrix2, size2); //Free the second matrix

    printf("\n-Multiplied matrix: \n");
    PrintMatrix(matrix3, size1, size3);

    FreeMatrix(&matrix3, size1);
    FreeMatrix(&matrix1, size1);
}

void BuildMatrix(int*** pMat, int row, int col) 
{
    int i, j;
    (*pMat) = (int**)malloc(row * sizeof(int*));
    if (*pMat == NULL) 
    {
        free(pMat);
        printf("*Not enough RAM.\nTerminating.\n");
        exit(1);
    }

    for (i = 0; i < row; i++) 
    {
        (*pMat)[i] = malloc(col * sizeof(int));
        if ((*pMat)[i] == NULL) {
            printf("*Not enough RAM.\nTerminating.\n");
            FreeMatrix(pMat, row);
            exit(1);
        }
        for (j = 0; j < col; j++) {
            printf("-Enter %d element in %d row: ", j + 1, i + 1);
            scanf("%d", &(*pMat)[i][j]);
        }
        printf("\n");
    }
    //FreeMatrix(pMat, row);
}

void FreeMatrix(int*** matrix, int row)
{
    for (int i = 0; i < row; i++)
    {
        free((matrix)[i]);
    }
    free(matrix);
}

void PrintMatrix(int** pMat, int row, int col) 
{
    for (int i = 0; i < row; ++i) 
    {
        for (int j = 0; j < col; ++j) 
        {
            printf("%d ", pMat[i][j]);
        }
        printf("\n");
    }
}

int** MultiplyMatrixes(int** a, int** b, int size1, int size2, int size3)
{
    int i, j, k, ** c = NULL;
    c = malloc(size1 * sizeof(int*));
    if (c == NULL) 
    {
        free(*c);
        printf("*Not enough RAM.\nTerminating.\n");
        exit(1);
    }

    for (i = 0; i < size1; i++) {
        c[i] = malloc(size3 * sizeof(int));
        if (c[i] == NULL) 
        {
            printf("*Not enough RAM.\nTerminating.\n");
            FreeMatrix(&c, size1);
            exit(1);
        }

        for (j = 0; j < size3; j++) 
        {
            c[i][j] = 0;
            for (k = 0; k < size2; k++) 
            {
                c[i][j] += (a[i][k] * b[k][j]);
            }
        }
    }
}

The error list: enter image description here

1. List item

Severity    Code    Description Project File    Line    Suppression State
Warning C4101   'newRow': unreferenced local variable   Project8    C:\Users\Shai\source\repos\Project8\Project8\Source1.c  13  
Warning C6011   Dereferencing NULL pointer 'c'.     Project8    C:\USERS\SHAI\SOURCE\REPOS\PROJECT8\PROJECT8\SOURCE1.C  96  
Warning C4715   'MultiplyMatrixes': not all control paths return a value    Project8    C:\Users\Shai\source\repos\Project8\Project8\Source1.c  119 

You're missing "#include <stdio.h>", so printf and scanf are unrecognized. when declaring a function like you did at the top of the code you need to give your variables names just like the signature when you made the function itself:

void BuildMatrix(int*** pMat, int row, int col);
void PrintMatrix(int** pMat, int row, int col);
int** MultiplyMatrixes(int** a, int** b, int size1, int size2, int size3);
int** MultiplyMatrixes(int** a, int** b, int size1, int size2, int size3);
void FreeMatrix(int***pMat, int idk);

in the code you've given there's no FreeMatrix by the way make sure you have that function in your code