Trying to create a JSONObject ends with a Cannot evaluate org.json.JSONObject.toString()

I've been following a tutorial (honestly, I was copy pasting, therefore I don't know why it doesn't work as I didn't change a thing) and I have this String response that I need to convert into a Json Object.

response =

Config.php\r\n{"error":false,"user":{"name":"test","surname":"test","address":"test","email":"test"}}

Right after the try at JSONObject jObj = new JSONObject(response); my program jumps to the exception with a message:

Method threw 'java.lang.NullPointerException' exception. Cannot evaluate org.json.JSONObject.toString()

Is it the structure of response or something?

Here's where I use it:

@Override
            public void onResponse(String response) {
                Log.d(TAG, "Login Response: " + response.toString());
                hideDialog();

                try {
                    JSONObject jObj = new JSONObject(response);
                    boolean error = jObj.getBoolean("error");

                    // Check for error node in json
                    if (!error) {
                        // user successfully logged in
                        // Create login session
                        session.setLogin(true);

                        // Now store the user in SQLite

                        JSONObject user = jObj.getJSONObject("user");
                        String name = user.getString("name");
                        String surname = user.getString("surname");
                        String address = user.getString("address");
                        String email = user.getString("email");

                        // Inserting row in users table
                        db.addUser(name, surname, address, email);

                        // Launch main activity
                        Intent intent = new Intent(LoginScreen.this,
                                MainMenu.class);
                        startActivity(intent);
                        finish();
                    } else {
                        // Error in login. Get the error message
                        String errorMsg = jObj.getString("error_msg");
                        Toast.makeText(getApplicationContext(),
                                errorMsg, Toast.LENGTH_LONG).show();
                    }
                } catch (JSONException e) {
                    // JSON error
                    e.printStackTrace();
                    Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
                }

            }