How to fix Debug error "Run-Time check failure"

Question

I'm creating a programme about drone.I got no error when building it but when it comes to debugging this error appears

Can anyone explain to me why this happens? and how to solve this? I'm sorry if my coding line is hard to understand and not organized because im still learning.And i do know that the coding line itself doesnt make sense (drone part) thank you so much

    #include<iostream>
    #include <fstream>
    #include <cstdlib>
    #include <iomanip>

    using namespace std;

    void manualMode();
    void defaultMode();


    int speed, timeTofly, operation;
    int angle = 90;

    int main() {
        int mode = 0, part = 3;
        double flyLevel;
        int obstacleSensor = 0, timer = 3, AccelerometerSensor = 0, tempSensor = 25;
        char startPause;
        cout << "Drone Flying Technology" << endl;
        do {
            cout << "Choose Mode: (1)Default, (2)Manual \n";
            cin >> mode;
            if (mode == 1)
                defaultMode();
            if (mode == 2)
                manualMode();
        } while (mode == 0);

        cout << "Choose how to fly: (1)Upper , (2)Lower , (3)Upper and Lower \n";
        cin >> part;
        switch (part) {
        case 1:
        case 2:
            flyLevel = 0.5;
            break;
        case 3:
            flyLevel = 1;
            break;
        }
        if (obstacleSensor == 0) {
            do {
                cout << "Press (S) to Start,and swing the propeller." << endl;
                cin >> startPause;
                cout << "LED is On\n";
                while (AccelerometerSensor != flyLevel) {
                    AccelerometerSensor++;
                }
                cout << "Flying session Started! Time Left:" << timeTofly << endl;
                cout << "Eagle eye Operation Started!\n";
                timeTofly = timeTofly / 2;
                cout << "Crusing mode initiate Time Left:" << timeTofly << endl;
                timeTofly = timeTofly / 2;
                cout << "Free fly commenced Time Left:" << timeTofly << endl;
                timeTofly = 0;
                startPause = 'P';
            } while ((startPause == 's') || (startPause == 'S'));
        }
        cout << "End!\nLED is Off";
        return 0;
    }


    void manualMode() {
        cout << "Enter drone speed (knot) \n";
        cin >> speed;
        cout << "Enter Time to fly: \n";
        cin >> timeTofly;
        cout << "Choose Operation: (1)Fully manual, (2)Normal Orientation, (3)Free orientation, (4)FPV racing, (5)All\n";
        cin >> operation;
    }
    void defaultMode() {
        int howtofly;
        cout << "how to fly: (1)Circle, (2)Altitude Hold, (3)Free orientation";
        cin >> howtofly;
        switch (howtofly) {
        case 1:
            speed = 30;
            timeTofly = 3;
            break;
        case 2:
            speed = 40;
            timeTofly = 3;
            break;
        case 3:
            speed = 60;
            timeTofly = 3;
            break;
        }


        char object[25];
        char imei[5];
        float m1;

        ofstream outputFile("object to record and preferred speed.txt", ios::out);
        cout << "Please enter object to record,your drone imei number and video frame per second:\n";
        cout << "\nPress <ctrl> + z to stop. \n";

        while (cin >> object >> imei >> m1)
        {
            outputFile << object << " " << imei << " " << m1 <<endl;
        }





    }