has triggered a breakpoint

При выполнении выдаёт ошибку

has triggered a breakpoint

Как это исправить?

#include "stdafx.h"
#include <stdio.h>
#define MAX_STR_SIZE 0x666  // Maximum string length
#define MIN_STR_SIZE 0x5    // Minimum string length
#pragma warning(disable:4996)
int main()
{
    int ch;
    int count = 0;
    int p = 0;
    FILE *fp;
    char buff[MAX_STR_SIZE];
    if ((fp = fopen("C:\asm\123.txt", "rb")) == NULL)
        while ((ch = getc(fp)) != EOF)
        {
            if (ch<' ' || ch>'z')
            {
                if (count>(MIN_STR_SIZE - 2))
                    if (count>p)
                    {
                        printf(&buff[0]);
                    }
                    else
                    {
                        printf("%08x:%s\n", ftell(fp), &buff[0]);
                    }
                p = 0; count = 0;
            }
            else
            {
                buff[p++] = ch; buff[p] = 0; count++;
                if (p == (MAX_STR_SIZE - 1))
                {
                    printf("%08x:%s\n", ftell(fp), &buff[0]);
                    p = 0;
                }
            }
        }
    return 0;
}