title: You must create this type of ParseObject using ParseObject.create() or the proper subclass. - crashed app but code is correct
body: <p>When i'm trying to log in error appears and aplication is closing.</p>
  
  <p>java.lang.IllegalArgumentException: You must create this type of ParseObject using ParseObject.create() or the proper subclass.</p>
  
  <p>This is communicate and its showing me that ParseUser user = new ParseUser(); is wrong but its not.</p>
  
  <pre><code>public class RegisterScreen extends AppCompatActivity {
  
      EditText edUsernameReg,edPasswordReg;
      Button registerBtn;
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_register_screen);
  
          edUsernameReg = (EditText)findViewById(R.id.edUsernameReg);
          edPasswordReg = (EditText)findViewById(R.id.edPasswordReg);
          registerBtn = (Button)findViewById(R.id.registerBtn);
  
          registerBtn.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  String username = edUsernameReg.getText().toString();
                  String password = edPasswordReg.getText().toString();
  
                  ParseUser user = new ParseUser();
                  user.setUsername(username);
                  user.setPassword(password);
                  user.signUpInBackground(new SignUpCallback() {
                      @Override
                      public void done(ParseException e) {
                          if(e == null){
                              Toast.makeText(getApplicationContext(),"Parse signup error", Toast.LENGTH_SHORT).show();
                          }else{
                              Toast.makeText(getApplicationContext(),"Successfully registered!", Toast.LENGTH_SHORT).show();
                              Intent intent = new Intent(RegisterScreen.this,LoginScreen.class);
                              startActivity(intent);
                          }
                      }
                  });
              }
          });
      }
  }
  </code></pre>
  
  <p>I was looking for tutorials but all of them are based exactly on documentation so am i. Please help.</p>