After adding "requestWindowFeature", I can't open Ribbit

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setContentView(R.layout.activity_login);

        mSignUpTextView=(TextView)findViewById(R.id.signupText);
        mSignUpTextView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(LoginActivity.this,SignupActivity.class);
                startActivity(intent);
            }
        });
        mUsername= (TextView) findViewById(R.id.usernameField);
        mPassword= (TextView) findViewById(R.id.passwordField);
        mLoginButton= (Button) findViewById(R.id.loginButton);

        mLoginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String username=mUsername.getText().toString();
                String password=mPassword.getText().toString();

                username=username.trim();
                password=password.trim();

                if(username.isEmpty() || password.isEmpty() ) {
                    AlertDialog.Builder builder = new AlertDialog.Builder(LoginActivity.this);
                    builder.setMessage(R.string.login_error_message)
                            .setTitle(R.string.login_error_title)
                            .setPositiveButton(android.R.string.ok,null);
                    AlertDialog dialog=builder.create();
                    dialog.show();
                }
                else{
                    setProgressBarIndeterminateVisibility(true);

                    ParseUser.logInInBackground(username, password,new LogInCallback() {
                        @Override
                        public void done(ParseUser user, ParseException e) {
                            setProgressBarIndeterminateVisibility(false);

                            if(e==null){
                                //success
                                Intent intent=new Intent(LoginActivity.this,MainActivity.class);
                                //clear history in case user touch "go back" button
                                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
                                startActivity(intent);
                            }else{
                                AlertDialog.Builder builder = new AlertDialog.Builder(LoginActivity.this);
                                builder.setMessage(e.getMessage())
                                        .setTitle(R.string.login_error_title)
                                        .setPositiveButton(android.R.string.ok, null);
                                AlertDialog dialog=builder.create();
                                dialog.show();
                            }
                        }
                    });
                }
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_login, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}