Необработанное исключение по адресу 0x7C5101C9 (ucrtbased.dll) в EXAM.exe: 0xC0000005: нарушение прав доступа при записи

struct Book
{
    int id = 0;
    int id_person_took = 0;                             //id of the person has taken the book
 
    int year_of_publishing;
    char* title;
    char* author;
    char* genre;
    double price;
    double rate;
 
    bool isTaken = false;                               //is this book belongs to reader
};
 
struct Date
{
    int day;
    char* month;
    int year;
};
 
struct Reader
{
    int reader_id = 0;
    int books_read = 0;
 
    char* surname;
    char* name;
    char* patronymic;
 
    char* fio;
 
    Date birthday;
    char* passport_id;
 
    int quant_books_on_hand = 0;
    int* books_on_hand_id = nullptr;                     //array IDs of books 
    bool isOwnBook = false;                              //is the reader has at least one book
    int* date_took_book = nullptr;                       //the date when a person took a book
    double owe = 0;                                      //if person delay returning the book
};
 
 
void FreeMemory(Book* arr_book, Reader* arr_reader, const int& size_book, const int& size_reader)
{
    for (int i = 0; i < size_book; i++)
    {
        delete[]arr_book[i].author;
        delete[]arr_book[i].genre;
        delete[]arr_book[i].title;
    }
 
    for (int i = 0; i < size_reader; i++)
    {
        delete[]arr_reader[i].birthday.month;
        delete[]arr_reader[i].fio;
        delete[]arr_reader[i].name;
        delete[]arr_reader[i].patronymic;
        delete[]arr_reader[i].date_took_book;
        delete[]arr_reader[i].books_on_hand_id;
    }
 
    if (size_book)
        delete[]arr_book;
    if (size_reader)
        delete[]arr_reader;
}
 
void SaveLibrary(Book* arr_book, Reader* arr_reader, int size_book, int size_reader, const int& id_book, const int& id_reader)
{
    FILE* f = fopen("save.bin", "wb");
 
    if (f)
    {
        int len = 0;
 
        fwrite(&id_book, sizeof(int), 1, f);
        fwrite(&size_book, sizeof(int), 1, f);
 
        for (int i = 0; i < size_book; i++)
        {
            len = strlen(arr_book[i].author) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_book[i].author, sizeof(char), len, f);
 
            len = strlen(arr_book[i].genre) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_book[i].genre, sizeof(char), len, f);
 
            len = strlen(arr_book[i].title) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_book[i].title, sizeof(char), len, f);
 
            fwrite(&arr_book[i].id, sizeof(int), 1, f);
            fwrite(&arr_book[i].id_person_took, sizeof(int), 1, f);
            fwrite(&arr_book[i].isTaken, sizeof(bool), 1, f);
            fwrite(&arr_book[i].price, sizeof(double), 1, f);
            fwrite(&arr_book[i].rate, sizeof(double), 1, f);
            fwrite(&arr_book[i].year_of_publishing, sizeof(int), 1, f);
        }
 
        fwrite(&id_reader, sizeof(int), 1, f);
        fwrite(&size_reader, sizeof(int), 1, f);
 
        for (int i = 0; i < size_reader; i++)
        {
            len = strlen(arr_reader[i].birthday.month) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_reader[i].birthday.month, sizeof(char), len, f);
 
            len = strlen(arr_reader[i].fio) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_reader[i].fio, sizeof(char), len, f);
 
            len = strlen(arr_reader[i].name) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_reader[i].name, sizeof(char), len, f);
 
            len = strlen(arr_reader[i].patronymic) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_reader[i].patronymic, sizeof(char), len, f);
 
            len = strlen(arr_reader[i].surname) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_reader[i].surname, sizeof(char), len, f);
 
            len = strlen(arr_reader[i].passport_id) + 1;
            fwrite(&len, sizeof(int), 1, f);
            fwrite(arr_reader[i].passport_id, sizeof(char), len, f);
 
            fwrite(&arr_reader[i].reader_id, sizeof(int), 1, f);
            fwrite(&arr_reader[i].books_read, sizeof(int), 1, f);
            fwrite(&arr_reader[i].birthday.day, sizeof(int), 1, f);
            fwrite(&arr_reader[i].birthday.year, sizeof(int), 1, f);
            fwrite(&arr_reader[i].isOwnBook, sizeof(bool), 1, f);
            fwrite(&arr_reader[i].owe, sizeof(double), 1, f);
 
            fwrite(&arr_reader[i].quant_books_on_hand, sizeof(int), 1, f);
 
            for (int j = 0; j < arr_reader[i].quant_books_on_hand; j++)
            {
                fwrite(&arr_reader[i].books_on_hand_id[j], sizeof(int), 1, f);
                fwrite(&arr_reader[i].date_took_book[j], sizeof(int), 1, f);
            }
        }
 
        fclose(f);
    }
}
 
void LoadLibrary(Book*& arr_book, Reader*& arr_reader, int& size_book, int& size_reader, int& id_book, int& id_reader)
{
    FILE* f = fopen("save.bin", "rb");
 
    if (f)
    {
        FreeMemory(arr_book, arr_reader, size_book, size_reader);
 
        fread(&id_book, sizeof(int), 1, f);
        fread(&size_book, sizeof(int), 1, f);
 
        arr_book = new Book[size_book];
        int len = 0;
 
        for (int i = 0; i < size_book; i++)
        {
            fread(&len, sizeof(int), 1, f);
            arr_book[i].author = new char[len] ;
            fread(arr_book[i].author, sizeof(char), len, f);
 
            fread(&len, sizeof(int), 1, f);
            arr_book[i].genre = new char[len] ;
            fread(arr_book[i].genre, sizeof(char), len, f);
 
            fread(&len, sizeof(int), 1, f);
            arr_book[i].title = new char[len] ;
            fread(arr_book[i].title, sizeof(char), len, f);
 
            fread(&arr_book[i].id, sizeof(int), 1, f);
            fread(&arr_book[i].id_person_took, sizeof(int), 1, f);
            fread(&arr_book[i].isTaken, sizeof(bool), 1, f);
            fread(&arr_book[i].price, sizeof(double), 1, f);
            fread(&arr_book[i].rate, sizeof(double), 1, f);
            fread(&arr_book[i].year_of_publishing, sizeof(int), 1, f);
        }
 
        fread(&id_reader, sizeof(int), 1, f);
        fread(&size_reader, sizeof(int), 1, f);
 
        arr_reader - new Reader[size_reader];
 
        for (int i = 0; i < size_reader; i++)
        {
            fread(&len, sizeof(int), 1, f);
            arr_reader[i].birthday.month = new char[len];
            fread(arr_reader[i].birthday.month, sizeof(char), len, f);
 
            fread(&len, sizeof(int), 1, f);
            arr_reader[i].fio = new char[len];
            fread(arr_reader[i].fio, sizeof(char), len, f);
 
            fread(&len, sizeof(int), 1, f);
            arr_reader[i].name = new char[len];
            fread(arr_reader[i].name, sizeof(char), len, f);
 
            fread(&len, sizeof(int), 1, f);
            arr_reader[i].patronymic = new char[len];
            fread(arr_reader[i].patronymic, sizeof(char), len, f);
 
            fread(&len, sizeof(int), 1, f);
            arr_reader[i].surname = new char[len];
            fread(arr_reader[i].surname, sizeof(char), len, f);
 
            fread(&len, sizeof(int), 1, f);
            arr_reader[i].passport_id = new char[len];
            fread(arr_reader[i].passport_id, sizeof(char), len, f);
 
            fread(&arr_reader[i].reader_id, sizeof(int), 1, f);
            fread(&arr_reader[i].books_read, sizeof(int), 1, f);
            fread(&arr_reader[i].birthday.day, sizeof(int), 1, f);
            fread(&arr_reader[i].birthday.year, sizeof(int), 1, f);
            fread(&arr_reader[i].isOwnBook, sizeof(bool), 1, f);
            fread(&arr_reader[i].owe, sizeof(double), 1, f);
 
            fread(&arr_reader[i].quant_books_on_hand, sizeof(int), 1, f);
 
            arr_reader[i].books_on_hand_id = new int[arr_reader[i].quant_books_on_hand];
            arr_reader[i].date_took_book = new int[arr_reader[i].quant_books_on_hand];
 
            for (int j = 0; j < arr_reader[i].quant_books_on_hand; j++)
            {
                fread(&arr_reader[i].books_on_hand_id[j], sizeof(int), 1, f);
                fread(&arr_reader[i].date_took_book[j], sizeof(int), 1, f);
            }
 
            fclose(f);
        }
 
    }
}