Access violation reading location

#include <iostream>
#include "game.h"

using namespace std;

int main(){
	system("chcp 1250");
	system("cls");

	Game* g = new Game();
	g->load_state_game();
	system("pause");
	return 0;
}

#include <iostream>
#include <string>

using namespace std;

class User{
private:
	struct age{
		int day;
		int month;
		int year;
	};
	struct user_data{
		string nick;
		string name;
		string surname;
		age a;
		string password;
		string email;
	};

	user_data u;

public:
	User();
	User(string, string, string, int, int, int, string, string);
	~User();

	user_data getData();
};

#include "user.h"

User::User(){}

User::User(string n, string na, string s, int d, int m , int y , string p , string e){

	u.nick = n;
	u.name = na;
	u.surname = s;
	u.a.day = d;
	u.a.month = m;
	u.a.year = y;
	u.password = p;
	u.email = e;
}

User::~User(){}

User::user_data User::getData(){
	return u;
}

#include <iostream>
#include <string>
#include <conio.h>
#include <fstream>
#include "user.h"

using namespace std;

class Game{
	private:
		
	public:
		Game();
		~Game();
		
		User* u;

		int log_in();
		int registration();
		void save_state_game();
		void load_state_game();
		void menu();
};

#include "game.h"

Game::Game(){}
Game::~Game(){}

int Game::log_in(){
	string login, hasło;

	cout<<"Money Maker version 1.0"<<endl;
	cout<<"-----------------------"<<endl;
	cout<<"Login: ";
	cin>>login;
	cout<<"Password: ";
	cin>>hasło;
	cout<<"-----------------------"<<endl;

	if(login==u->getData().nick)
		if(hasło==u->getData().password)
			cout<<"Dziękuję"<<endl;
		else cout<<"Błęde hasło :("<<endl;
	else cout<<"Błędny login :("<<endl;
	return 0;
}
int Game::registration(){

	string n, na, s, p, e;
	int d, m ,y; 
	bool is_good_data=false;
	int correct_answer=0;

	do{
		system("cls");

		cout<<"Registration to Money Maker"<<endl;
		cout<<"-----------------------"<<endl;
		cout<<"Nick: ";
		cin>>n;
		cout<<"Password: ";
		cin>>p;
		cout<<"Your real name: ";
		cin>>na;
		cout<<"Your real surname: ";
		cin>>s;
		cout<<"E-mail: ";
		cin>>e;
		cout<<"Day of birth: ";
		cin>>d;
		cout<<"Month of birth: ";
		cin>>m;
		cout<<"Year of birth: ";
		cin>>y;
		cout<<"-----------------------"<<endl;

		// Sprawdzanie poprawności email
		bool is_good_email=false;

		for(int i = 0; i<e.length();++i)
			if((e[i]=='@'))
				is_good_email=true;

		//-------------------------------

		if(n.length()>=5 && n.length()<=100){ // Nick
			correct_answer++;
		}
		else {cout<<"Invalid nick"<<endl;}

		if(p.length()>=5 && p.length()<=100){ // Password
			correct_answer++;
		}
		else {cout<<"Invalid password"<<endl;}

		if((e.length()>=5 && e.length()<=100) && is_good_email){ // Email
			correct_answer++;
		}
		else {cout<<"Invalid email"<<endl;}

		if(d>=1 && d<=31){ // Day
			correct_answer++;
		}
		else {cout<<"Invalid day of birth"<<endl;}

		if(m>=1 && m<=12){ // Month
			correct_answer++;
		}
		else {cout<<"Invalid month of birth"<<endl;}

		if(y>=1900 && y<=1995){ // Year
			correct_answer++;
		}
		else {cout<<"You're too young :("<<endl;}

		if(correct_answer==6)
			is_good_data=true;

		}while(!is_good_data);

		if(is_good_data){
			u = new User(n, na, s, d, m, y, p, e);
			cout<<u->getData().name<<", Your account is created"<<endl;
			save_state_game();
			cout<<"-----------------------"<<endl;
			system("pause");
		}

		return 0;
	}

void Game::save_state_game(){
	
	try{
		ofstream DATA_FILE;
		DATA_FILE.open("db.mdb", ios::out | ios::binary);

		cout<<"Size of User object is: "<<sizeof(*u)<<endl;

		DATA_FILE.write((char* )u, sizeof(*u));
		DATA_FILE.close();

		cout<<"Object u was saved succesfully"<<endl;

	}
	catch(exception X) { cout<<"Could not save :("<<endl;}
}

void Game::load_state_game(){

	u = new User();

	try{
		ifstream DATA_FILE;
		DATA_FILE.open("db.mdb", ios::in | ios::binary);

		cout<<"Size of User object is: "<<sizeof(*u)<<endl;

		DATA_FILE.read((char* )u, sizeof(*u));
		DATA_FILE.close();

		cout<<"Document loaded :)"<<endl;

		cout<<u->getData().email<<endl; // Tutaj najprawdopodobniej tkwi problem 

	}catch(exception X) {cout<<"Could not load :("<<endl;}

}
	void Game::menu(){
		int wybór;
		cout<<"Money Maker version 1.0"<<endl;
		cout<<"-----------------------"<<endl;
		cout<<"What will you do?"<<endl<<endl;
		cout<<"(1) Login"<<endl;
		cout<<"(2) Register"<<endl;
		cout<<"-----------------------"<<endl;
		cin>>wybór;

		switch(wybór){
		case 1: log_in(); break;
		case 2: registration(); break;
		default: cout<<"Invalid character"<<endl;
		}
	}