Custom authentication deserialization failed: Unexpected character encountered while parsing value - php

Question

I'm having trouble creating a Custom Authentication! I'm using a free host from 000WebHost to test Photon's multiplayer on Unity, but I get the following error in Unity debug:
OperationResponse 230: ReturnCode: 32755 (Custom authentication deserialization failed: Unexpected character encountered while parsing value: U. Path '', line 0, position 0.).
Parameters: {} Server: NameServer Address: ns.exitgames.com:5058
UnityEngine.Debug:LogError(Object)
Photon.Realtime.LoadBalancingClient:DebugReturn(DebugLevel, String) (at Assets/Photon/PhotonRealtime/Code/LoadBalancingClient.cs:1835)
Photon.Realtime.LoadBalancingClient:OnOperationResponse(OperationResponse) (at Assets/Photon/PhotonRealtime/Code/LoadBalancingClient.cs:1909)
ExitGames.Client.Photon.PeerBase:DeserializeMessageAndCallback(StreamBuffer) (at C:/Dev/photon-sdk-dotnet/PhotonDotnet/PeerBase.cs:616)
ExitGames.Client.Photon.EnetPeer:DispatchIncomingCommands() (at C:/Dev/photon-sdk-dotnet/PhotonDotnet/EnetPeer.cs:545)
ExitGames.Client.Photon.PhotonPeer:DispatchIncomingCommands() (at C:/Dev/photon-sdk-dotnet/PhotonDotnet/PhotonPeer.cs:1473)
Photon.Pun.PhotonHandler:FixedUpdate() (at Assets/Photon/PhotonUnityNetworking/Code/PhotonHandler.cs:130)
My Unity authentication code:
using Photon.Pun;
using Photon;
public class Login : MonoBehaviour {
public InputField User_Input;
public InputField Pass_Input;
public Text Error_Text;
public string username;
public string password;
public void UserName(){
username = User_Input.text.ToString ();
}
public void UserPass(){
password = Pass_Input.text.ToString ();
}
public void SubmitLogin(){
PhotonNetwork.AuthValues = new AuthenticationValues ();
PhotonNetwork.AuthValues.AuthType = CustomAuthenticationType.Custom;
PhotonNetwork.AuthValues.AddAuthParameter ("username", username);
PhotonNetwork.AuthValues.AddAuthParameter ("password", password);
PhotonNetwork.ConnectUsingSettings();
}
void OnJoinedLooby(){
Debug.Log ("We did it");
}
void OnGUI(){
GUILayout.Label (PhotonNetwork.connectionStateDetailed.ToString ());
}
}
My server-side code:
<?php
include "db.php";
$username = $_GET['username'];
$password = $_GET['password'];
$check = mysqli_query($conn , "SELECT * FROM accounts WHERE `username`='".$username."'");
$numrows = mysqli_num_rows($check);
if ($numrows == 0){
die ("Username does not exist.");
}else{
$password = md5($password);
while($row = mysqli_fetch_assoc($check)){
if ($password == $row['password']){
$login_info = array(
"ResultCode" => 1,
"Message" => "You are connected!");
}else{
$login_info = array(
"ResultCode" => 2,
"Message" => "Wrong username or password");
}
}
}
$json = json_encode($login_info);
echo $json;
?>
In the photon panel I placed Url mydomain/auth.php and I did not put any optional Key/Value Pairs
I do not know what the problem is, if anyone knows

Answer 1

I replied on our forum. Posting the same here:
The letter "U" is a hint that it could be from "Username does not exist.".
Replace
die ("Username does not exist.");
with
$login_info = array(
"ResultCode" => 3,
"Message" => "Username does not exist."
);
If the issue persists, use postman and send an HTTP request with proper query string values to your server and see what it returns. Fix that.