Aapke saare files (PHP, CSS, JS, aur .htaccess) ko mila kar check karne ke baad, **Error 500** ke mukhya kaaran aur unka samadhan niche diya gaya hai. Aapne code bahut achha likha hai, lekin production server (Hostinger) par kuch chhoti cheezein crash kar rahi hain.

### 1. Vendor Folder aur Composer (Sabse Badi Wajah)
Aapke `database.php` aur `mail.php` mein `vendor/autoload.php` ko call kiya gaya hai.
* **Galti:** Agar aapne Hostinger par `vendor` folder upload nahi kiya hai, toh PHP ko `Firebase` aur `PHPMailer` ki libraries nahi milengi, aur server turant **Error 500** de dega.
* **Solution:** Apne computer par `composer install` chalayein aur jo `vendor` folder bane, use Hostinger ke `public_html` (ya jahan aapki files hain) ke bahar ya barabar upload karein.

### 2. File Paths ki Galti (Directory Structure)
Aapne `header.php` mein call kiya hai: `require_once __DIR__ . '/../config/session.php';`.
Lekin `auth.php` mein call kiya hai: `require_once __DIR__ . '/database.php';`.
* **Galti:** Agar aapki files ka structure sahi nahi hai, toh `require_once` fail ho jayega.
* **Sahi Structure:**
    ```text
    / (root)
    ├── config/
    │   ├── auth.php
    │   ├── database.php
    │   ├── mail.php
    │   ├── session.php
    │   └── firebase-credentials.json
    ├── includes/
    │   ├── functions.php
    │   ├── header.php
    │   ├── sidebar.php
    │   └── footer.php
    ├── vendor/ (Iska hona bahut zaroori hai)
    ├── index.php
    └── dashboard.php
    ```

### 3. Firebase Credentials JSON
`database.php` mein line hai: `$serviceAccountPath = __DIR__ . '/firebase-credentials.json';`.
* **Galti:** Agar aapne Firebase console se download ki hui JSON file ko rename karke `config` folder mein nahi dala hai, toh connection fail ho jayega.
* **Solution:** JSON file ko `config` folder mein rakhein.

### 4. .htaccess Custom Error Pages
Aapke `.htaccess` mein ye lines hain:
[cite_start]`ErrorDocument 500 /shayari/500.php`[cite: 1].
* **Galti:** Agar `/shayari/` naam ka folder nahi hai ya `500.php` file missing hai, toh server "Error 500" dikhane ki koshish mein "Recursive Error" mein phans jayega aur crash ho jayega.
* **Solution:** In lines ko temporary hata dein ya check karein ki path sahi hai.

### 5. SMTP Password aur Mail Config
`mail.php` mein aapne password `YourStrongPasswordHere` rakha hai.
* **Galti:** Agar ye sahi nahi hai, toh `Auth.php` mein jab `sendOTP` call hoga, toh PHPMailer error dega jo handle na hone par server crash kar sakta hai.

---

### 🔥 Turant Check Karne Ka Tarika (Debugging)
Error 500 ko khatam karne ke liye, **`index.php`** ke sabse upar (yani `<?php` ke turant baad) ye code dalein:

```php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
```

Ise dalne ke baad jab aap page refresh karenge, toh "Error 500" ki jagah **asli error** (jaise: *Failed to open stream: No such file...*) likha hua aayega.

### Agla Kadam:
1. Kya aapne **`vendor`** folder upload kiya hai?
2. Kya **`firebase-credentials.json`** file `config` folder ke andar maujood hai?

Mujhe bataiye ki debugging code dalne ke baad kya error message aa raha hai, main use turant theek karwa dunga.<br />
<b>Warning</b>:  require_once(/home/u395065556/domains/kasppra.com/public_html/shayari/vendor/autoload.php): Failed to open stream: No such file or directory in <b>/home/u395065556/domains/kasppra.com/public_html/shayari/config/mail.php</b> on line <b>3</b><br />
<br />
<b>Fatal error</b>:  Uncaught Error: Failed opening required '/home/u395065556/domains/kasppra.com/public_html/shayari/vendor/autoload.php' (include_path='.:/opt/alt/php82/usr/share/pear:/opt/alt/php82/usr/share/php:/usr/share/pear:/usr/share/php') in /home/u395065556/domains/kasppra.com/public_html/shayari/config/mail.php:3
Stack trace:
#0 /home/u395065556/domains/kasppra.com/public_html/shayari/config/auth.php(4): require_once()
#1 /home/u395065556/domains/kasppra.com/public_html/shayari/index.php(12): require_once('/home/u39506555...')
#2 {main}
  thrown in <b>/home/u395065556/domains/kasppra.com/public_html/shayari/config/mail.php</b> on line <b>3</b><br />