Org.hibernate.MappingException: Could not determine type for: java.util.Collection

@Entity
public class Ticket extends BaseEntity {
 
    private String description;
    private String subject;
    private String customerName;
    private String customerEmail;
    private String groiup;
    private String team;
    private String type;
    private int relies;
    private int expert;
    @ManyToOne(optional=false, cascade= CascadeType.ALL)
    @JoinColumn(name = "user")
    private User user;
 
    public User getUser() { return user; }
 
    public void setUser(User user) { this.user = user; }
 
    public String getDescription() {
        return description;
    }
 
    public void setDescription(String description) {
        this.description = description;
    }
 
    public String getSubject() {
        return subject;
    }
 
    public void setSubject(String subject) {
        this.subject = subject;
    }
 
    public String getCustomerName() {
        return customerName;
    }
 
    public void setCustomerName(String customerName) {
        this.customerName = customerName;
    }
 
    public String getCustomerEmail() {
        return customerEmail;
    }
 
    public void setCustomerEmail(String customerEmail) {
        this.customerEmail = customerEmail;
    }
 
    public String getGroiup() {
        return groiup;
    }
 
    public void setGroiup(String groiup) {
        this.groiup = groiup;
    }
 
    public String getTeam() {
        return team;
    }
 
    public void setTeam(String team) {
        this.team = team;
    }
 
    public String getType() {
        return type;
    }
 
    public void setType(String type) {
        this.type = type;
    }
 
    public int getRelies() {
        return relies;
    }
 
    public void setRelies(int relies) {
        this.relies = relies;
    }
 
    public int getExpert() {
        return expert;
    }
 
    public void setExpert(int expert) {
        this.expert = expert;
    }
}

@Entity
public class User extends BaseEntity implements UserDetails {
 
    private static final long serialVersionUID = -4309721365940075858L;
 
    private String username;
    private String firstName;
    private String lastName;
    private String email;
    private String password;
    private String roleName;
    @OneToMany(mappedBy="user", cascade = CascadeType.ALL)
    private Collection<Ticket> tickets = new ArrayList<Ticket>();
 
    public Collection<Ticket> getTickets() {
        return tickets;
    }
 
    public void setTickets(Collection<Ticket> tickets) {
        this.tickets = tickets;
    }
 
    public String getRoleName(){ return roleName; }
 
    public void setRoleName(String roleName){ this.roleName = roleName; }
 
    public String getUsername() {
        return username;
    }
 
    public void setUsername(String username) {
        this.username = username;
    }
 
    public String getFirstName() {
        return firstName;
    }
 
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
 
    public String getLastName() {
        return lastName;
    }
 
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
 
    public String getEmail() {
        return email;
    }
 
    public void setEmail(String email) {
        this.email = email;
    }
 
    @Override
    @Transient
    public Collection<? extends GrantedAuthority> getAuthorities() {
        //return Arrays.asList(new SimpleGrantedAuthority("ROLE_ADMIN"));
        return Arrays.asList(new SimpleGrantedAuthority(roleName));
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
 
    @Override
    public String getPassword() {
        return this.password;
    }
 
    @Override
    @Transient
    public boolean isAccountNonExpired() {
        return true;
    }
 
    @Override
    @Transient
    public boolean isAccountNonLocked() {
        return true;
    }
 
    @Override
    @Transient
    public boolean isCredentialsNonExpired() {
        return true;
    }
 
    @Override
    @Transient
    public boolean isEnabled() {
        return true;
    }
 
    @Override
    @Transient
    public boolean equals(Object other){
        if (this == other)
            return true;
 
        if ( !(other instanceof User) )
            return false;
 
        User otherUser = (User) other;
        if(otherUser.username == this.username)
            return true;
        else return false;
    }
}

CREATE TABLE User (
    id BIGINT NOT NULL AUTO_INCREMENT,
    username varchar(45) NOT NULL,
    first_name varchar(45) DEFAULT NULL,
    last_name varchar(45) DEFAULT NULL,
    email varchar(45) DEFAULT NULL,
    password varchar(45) DEFAULT NULL,
    role_name varchar(45) DEFAULT 'ROLE_USER',
    update_date DATETIME,
    create_date DATETIME,
    PRIMARY KEY (id)
) ENGINE=InnoDB;

CREATE TABLE Ticket (
    id BIGINT NOT NULL AUTO_INCREMENT,
    description varchar(255) not null,
    subject varchar(255),
    customer_name varchar(255),
    customer_email varchar(255),
    groiup varchar(255),
    team varchar(255),
    type varchar(255),
    relies int,
    expert BIGINT,
    user BIGINT,
    update_date DATETIME,
    create_date DATETIME,
  PRIMARY KEY(id),
  foreign key(user) references user(id)
) ENGINE=InnoDB;

    @OneToMany(mappedBy="user", cascade = CascadeType.ALL)
    public Collection<Ticket> getTickets() {
        return tickets;
    }