How to Resolve Possible Cut and Paste Error.? [closed]

Question

Error with reference id in Android Studio. It shows that the id has already been looked up in this method. I have given the id name same as used in the code but it does not work. I have already tried chaining the id and reusing it but it shows the same error. Please need some help. The error message image is in the hyper link.

This is my code

public class SignUp extends AppCompatActivity implements View.OnClickListener {

    Button btnSignup;
    TextView btnLogin,btnForgotPass;
    EditText input_email,input_pass;
    RelativeLayout activity_sign_up;

    private FirebaseAuth auth;
    Snackbar snackbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sign_up);

        //View
        btnSignup = (Button)findViewById(R.id.signup_btn_register);
        btnLogin = (TextView)findViewById(R.id.signup_btn_login);
        btnForgotPass = (TextView)findViewById(R.id.signup_btn_forgot_pass);
        input_email = (EditText)findViewById(R.id.signup_email);
        input_pass = (EditText)findViewById(R.id.signup_password);
        activity_sign_up = (RelativeLayout)findViewById(R.id.activity_sign_up);
    }
}

Answer 1

Go to Build - > Rebuild Project if this doesnot work... go to File -> Invalidate cache/Restart...